Abstract:
A computer system and method for transmitting 10 Gigabit Ethernet (10GE) LAN signals over transport systems. Standard 10GE LAN signals are generated in any client IEEE 802.3 10GE LAN compliant interface. A transceiver receives the client 10GE LAN signal in the LAN format. The client 10GE LAN signals are not converted to a SONET transmission format at any time before reaching the transceiver. The transceiver then converts the client 10GE LAN signal to an internal electrical 10GE LAN signal before re-clocking the internal electrical LAN signal. The re-clocked internal electrical 10GE LAN signal is then re-modulated into a second 10GE LAN signal. The second 10GE LAN signal is then transmitted to a transport system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application is a continuation of U.S. patent application Ser. No. 10/357,606, entitled “Apparatus and Method for Transmitting 10 Gigabit Ethernet LAN Signals over a Transport System,” filed Feb. 4, 2003, which claims priority to Provisional Application Ser. No. 60/370,826, entitled “Apparatus and Method for Transmitting 10 Gigabit Ethernet LAN Signals Over a Long Haul DWDM System”, by Jeffrey Lloyd Cox and Samir Satish Seth, filed Apr. 8, 2002. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to a computer system for transmitting a 10 Gigabit Ethernet local area network (LAN) signal over a transport system without encapsulating the 10GE LAN signal into a Synchronous Optical Network (SONET) frame.  
       BACKGROUND OF THE INVENTION  
       [0003]     Data networks that cover large geographical distances have historically been fundamentally different from those that cover short distances. This fact primarily was derived from the different evolutionary paths that were followed by the Enterprise networks (ones that reside inside of a business, home, educational institution, or government agency) and the Carrier networks (ones that are provided by a common carrier). Over the past few decades the Enterprise networks and Carrier networks mostly evolved independently, each addressing a different problem and each following a different set of standards. The Enterprise networks mostly evolved to support data from computing environments via LAN infrastructures and data protocols. After decades of competition between different LAN standards and networking protocols during the 1980s and 1990s, the LANs are now predominantly built on Ethernet and Internet Protocol (IP) technologies. Ethernet is defined by the Institute for Electrical and Electronics Engineers (IEEE) and specifically is defined by the IEEE 802.3 standard. The Internet Engineering Task Force (IETF) defines IP.  
         [0004]     The Carrier networks mostly evolved to support voice services from home and business customers via various circuit-switched Time Domain Multiplexing (TDM) technologies. The Carrier networks are now predominantly comprised of various TDM technologies built on the Synchronous Optical Network (SONET) standard or its European counterpart Synchronous Digital Hierarchy (SDH). The American National Standard Institute (ANSI) defines SONET and the International Telecommunications Union (ITU) defines the SDH standard.  
         [0005]     Historically, the Ethernet LAN technologies provided very cost-effective high-speed “local” connections among computers, but sacrificed the ability to span distances longer than approximately 10 km. Typical Ethernet LANs spanned relatively small areas like a building or a campus. Such a transport system may be called an inter-office transport system. More recently, Ethernet has been used directly over optical fiber in Metropolitan Area Networks (MANs) to deliver Ethernet services natively to areas on the order of 100 km in diameter. The method on how to utilize Ethernet natively on optical fiber for distances shorter than approximately 100 km is specified by the IEEE 802.3 standard.  
         [0006]     As the need arose for the Enterprise LAN networks to interconnect their geographically separate facilities, the only available services at the Enterprise&#39;s disposal were from the public Carriers&#39; networks. However, the asynchronous, connectionless, packet-oriented nature of the LAN technology was mostly incompatible with the synchronous, connection-based, bit-oriented nature of the Carriers&#39; TDM facilities. To join the two technological worlds together, various data technologies were invented. In the realm where speeds are comparable to that of LANs (i.e. 10 Megabits/second or greater) Asynchronous Transfer Mode (ATM), Frame Relay (FR), and Packet over SONET (POS) became the most popular data technologies that Carriers utilized. ATM, FR, and POS are generally considered Wide Area Networking (WAN) technologies and are built on top of the SONET-based TDM infrastructure currently deployed by the carriers. In general, ATM, FR, and POS sacrificed the simplicity, efficiency, and cost-effectiveness of LAN technologies in order to be compatible with the existing carrier TDM infrastructure, which was primarily designed for voice traffic. At the time ATM, FR, and POS were being developed in the late 1980s, it made sense to make these sacrifices because the volume of data traffic over the TDM infrastructure was insignificant when compared to the volume of voice traffic. However, since the later part of the 1990&#39;s, data traffic has grown exponentially so that now it comprises the majority of the traffic on the Carrier&#39;s TDM infrastructure.  
         [0007]     Since Carriers adopted ATM, FR, and POS as the WAN technologies, Enterprise networks were forced to utilize these inefficient and expensive technologies to interconnect their LANs between their various locations. Typically the interconnections were accomplished via routers with ATM, FR, and POS interfaces and ATM switches, see  FIG. 1 . The introductions of these WAN technologies to the Enterprise&#39;s LAN infrastructures lead to significant new technological learning curves and significant capital and operational expenses. Many Enterprises created entirely separate departments to deal with the Carriers and their WAN technologies.  
         [0008]     As the Ethernet LAN technologies evolved, data rates grew from 10 Mbits/sec to 100 Mbits/sec, 1 Gbit/sec, and now 10 Gbit/sec Ethernet (10GE). Each successive generation of Ethernet remained compatible with the previous, thus allowing for interoperability as the network grew. Enterprises quickly adopted each new generation of Ethernet technology to support the exploding traffic volumes on their LANs. With the introduction of 10GE standard, Enterprise networks will once again scale to the next level. The high throughput rate of 10GE makes the technology extremely attractive for use on corporate backbone networks. Because the original packet format and minimum/maximum packet size were retained between the various versions of Ethernet, all forms of Ethernet interoperate seamlessly. Consequently it is possible, for example, to collect traffic from one hundred 100 Base-T Ethernets, each running at full speed, and pass this traffic along a single 10GE network.  
         [0009]     However, the Carrier WAN technologies have lagged behind the LAN Ethernet implementations in terms of capacity, price/performance, and ease of use. Enterprises have voiced their desire to implement Ethernet connections across WANs as a mechanism to supplant the traditional WAN technologies (ATM, FR, and POS) offered by Carriers. There are several potential mechanisms available to transport the various Ethernet technologies across WAN infrastructures. In general, these mechanisms can be broken into two categories: encapsulation and native. In the case of encapsulation, an Ethernet frame is removed from its native media format and encapsulated inside of the payload area of another protocol. There are numerous examples of the encapsulation approach including: Ethernet over FR, Ethernet over POS, Ethernet over SONET (x86, 10GE WAN, and others), and Ethernet over ATM (LANE). All of these encapsulation techniques were invented in order to allow Ethernet to be run over existing Carrier WAN technologies that, in turn, were transported on top of traditional Carrier TDM technologies, thus creating additional unnecessary layers of cost and complexity. The native Ethernet formats are defined by the IEEE 802.3 committee standards for each of the Ethernet variations. The physical layer (PHY) of the IEEE Ethernet standards defines how Ethernet is transmitted over a given media. For each of the Ethernet speeds (10 Mb, 100 Mb, 1 Gb, and 10 Gb) the IEEE defines at least one native PHY format that transports Ethernet directly on optical fiber facilities and at least one PHY format that transports Ethernet directly on copper facilities (coax or twisted pair media). In addition to various copper-based PHYs, each of the Ethernet speeds support multiple PHYs for optical fiber in order to support different reaches, different price points, and different optical fiber types. However, the IEEE-defined PHYs do not support: 
        1. Reaches beyond about 100 km     2. Optical media other than optical fiber     3. Media other than optical fiber or copper     4. Multiplexing multiple Ethernet signals over a given optical media.        
 
         [0014]     The 100 km limit on optical fiber is the approximate point at which an optical signal will degrade beyond the point of recovery without some form of signal regeneration. The IEEE 802.3 committee&#39;s charter ended at this point as they saw that distances beyond 100 km were in the realm of WAN technologies and they were a committee chartered to focus on LAN issues.  
         [0015]     When developing the 10GE standard, the IEEE 802.3ae committee developed two different 10GE frame formats. These frame formats are generally known as the “LAN” standard and the “WAN” standard, though these are somewhat misnamed terms. The 10GE “LAN” standard utilizes a native frame format identical to all previous IEEE 802.3 Ethernet standards. But, in order to allow compatibility with the existing SONET framing structure and data rate, the IEEE 802.3ae committee defined the 10GE “WAN” standard. The IEEE 802.3ae WAN standard encapsulates native Ethernet frames inside of an OC-192 SONET Payload Envelope (SPE) and adjusts the clock rate of the 10GE signal such that it is compatible with that of OC-192. Both the 10GE WAN and 10GE LAN standards support the same set of optical fiber PHYs and thus both have the same distance limitations on a single span of optical fiber without resorting to additional equipment. The “LAN” and “WAN” designations simply refer to their differences in framing format and data rates.  
         [0016]     To transport native Ethernet signals further than the nominal 100 km limit on optical fiber, and/or to support multiple optical Ethernet signals natively on a given optical fiber, other technologies must be introduced to multiplex, amplify, and condition the optical signal. The technologies that allow optical signals to cost-effectively travel beyond 100 km and/or be multiplexed on optical fiber are well known and have been applied to the SONET industry for well over a decade. These technologies include: optical amplification (via Erbium Doped Fiber Amplifiers (EDFA) or Raman amplifiers), dispersion compensation, optical multiplexing via Coarse Wave Division Multiplexing (CWDM, less than 17 channels) or Dense Wave Division Multiplexing (DWDM, greater than or equal to 17 channels), gain equalization, Forward Error Correction (FEC), and various modulation techniques. Combined, these technologies are generally referred to as Metro (less than 100 km in length), Long Haul (LH, between 100 and 1000 km), and Ultra Long Haul (ULH, greater than 1000 km) transport systems. Recent ULH systems allow more than 100 ten-gigabit signals to be transmitted  1000 &#39;s of kilometers over an optical fiber without the need to be converted to an electronic signal.  
         [0017]     Transport systems are that class of systems that allow a signal (or signals) to be transmitted and received via a media while including functionality beyond that of the original signal. An optical transport system may include optical fiber or free space optics. A fiber transport system can include fiber optics, copper wire, or any thread like substance, such as carbon fiber, capably of carrying a signal. Transport systems include support for functionality such as (but not limited to): 
        1. Media: optical fiber, Free Space Optics (FSO), Radio Frequency (RF), and electrical-based solutions (twisted copper pairs, coaxial cable)     2. Topological organizations: linear, rings, stars, and meshes     3. Switching capabilities: protection, restoration, and cross-connections     4. Multiplexing capabilities: single channel, CWDM, and DWDM     5. Directional capabilities: unidirectional or bi-directional     6. Distance capabilities: Metro, LH, ULH, submarine, and satellite systems     7. Transport system network elements: Optical Add/Drop Multiplexers (OADM), Optical Wavelength Cross-connects (OXC), and Regenerators (Regen)     8. Management and Control systems: signaling protocols, performance monitoring, and configuration and control interfaces        
 
         [0026]     These functionalities may be used independently or in various combinations to create a wide variety of transport system implementations to solve specific transport system problems.  
         [0027]     In the prior art, to adapt a standard IEEE 802.3 10GE client signal to a format that is suitable for a specific transport system, a device called a transceiver is employed. A transceiver converts the 10GE signal from a client system (the tributary signal) to a signal that is defined by the particular transport system (the line signal). Prior art transceivers such as those offered by Nortel, Lucent, Hitachi and others are available to convert 850, 1310 and 1550 nm optical tributary signals compatible with the 10GE WAN standard to the signals suitable for their respective Metro/LH/ULH systems. However, a need exists in the industry for a transceiver that is capable of receiving tributary signals of the 10GE LAN standard. In other words, a need exists for a high-speed transport system that is compatible with the 10GE LAN standard and does not require conversion to the IEEE 10GE WAN standard, or any other SONET-based standard, for use in creating networks.  
         [0028]     Prior art systems suffer from the ability of using the 10GE LAN standard for a high-speed transport system. For example, United States Patent No. 2001/0014104, to Bottorff, et al., entitled “10 Gigabit Ethernet Mappings For A Common Lan/Wan Pmd Interface With A Simple Universal Physical Medium Dependent Interface”, discloses an Ethernet mapping that enables high speed Ethernet data streams having a data rate of 10 Gb/s to be transported across a synchronous packet switched network having a standard SONET OC-192 line rate. The Bottorff invention, as with many of the other prior art inventions, requires conversion to a SONET-based standard.  
         [0029]     U.S. Pat. No. 6,075,634 to Casper, et al., entitled “Gigabit Data Rate Extended Range Fiber Optic Communication System And Transponder Therefor”, discloses a method and system for a fiber optic digital communication system and associated transponder architecture. The system interfaces Gigabit Ethernet digital data over an extended range fiber optic link, using digital data signal regeneration and optical signal processing components that pre- and post-compensate for distortion and timing jitter. Casper does not disclose a transceiver that is capable of receiving tributary signals of the 10GE LAN standard.  
         [0030]     U.S. Pat. No. 6,288,813 to Kirkpatrick, et al., entitled “Apparatus And Method For Effecting Data Transfer Between Data Systems”, discloses a receiver that converts an optical signal to digital data signals. The digital data signals are then converted to balanced bipolar signals and are then outputted onto buses for input into data systems. Kirkpatrick does not disclose an architecture for transporting 10GE LAN signals.  
       SUMMARY OF THE INVENTION  
       [0031]     The present invention is an improvement over the prior art because the invention provides a system and method for transmitting IEEE 10GE LAN signals over transport systems through a novel transceiver. Standard 10GE LAN tributary signals are generated by any IEEE 802.3 10GE LAN compliant client device or system. The transceiver receives the tributary 10GE LAN signal in its native format. The transceiver then converts the 10GE LAN signal to an internal electrical 10GE LAN signal and utilizes this signal to drive a second transport system signal (the line-side or line signal). The line-side 10GE LAN signal is then transmitted through the remainder of the transport system as a standard 10GE LAN signal with or without FEC.  
         [0032]     The invention further provides for performance monitoring (PM) of the received tributary and line-side optical signals, termination of the tributary and line signals (both transmit and receive), conversion of the tributary and line signals to and from internal electrical signals, electrically multiplexing and de-multiplexing signals, adding and removing FEC, clock and data recovery (CDR) of received signals, and in the case of optical line-side signals, control of laser wavelength locking and modulation of line optics.  
         [0033]     An exemplary use of the invention consists of the interconnection of two 10GE LAN client systems such as that known in the art. One example would be the Cisco Catalyst 6500 Ethernet switch with a 10GE LAN interface (the client interface). The Catalyst 10GE LAN interface is connected to an embodiment of the invention comprising of a 10GE LAN transceiver, which is in turn connected to a transport system. The transport system carries the 10GE LAN signal to the other end of the transport system where a second 10GE LAN transceiver coverts the signal to a second client signal that is attached to a second Catalyst 10GE LAN interface. Within each transceiver, the 10GE client signal is converted to and from an internal electrical signal via the PMD. The internal 10GE signal is performance monitored by a 10GE LAN Media Access Control (MAC) circuit. The internal 10GE signal is connected through a bus to and from a Forward Error Correction (FEC) circuit and subsequently to an electrical multiplexer (MUX) and from an electrical de-multiplexer (DMUX) where CDR is performed. The data from the electrical MUX is then communicated to a line optics module (LOM) in the transmitting direction of the line-side. The transmitting direction of the LOM consists of one or more drivers (electrical amplifiers) that modulate (either directly or via an external modulator) a laser contained in the LOM. The resulting modulated laser light is then placed onto the transport system. The receiving direction of the LOM consists of a detector and an electrical amplifier to boost the detected signal in the case where the detector&#39;s own electrical signal is insufficient to drive the remaining circuitry. Data from the electrical detector is then communicated to DMUX where CDR is performed and the signal is subsequently passed to the FEC circuit. The PMD, 10GE MAC, FEC circuit, MUX, DMUX, and LOM are all controlled from a central micro controller through a control bus.  
         [0034]     All of the above advantages make a high-speed transport system that is compatible with the 10GE LAN standard and does not require conversion to the IEEE 10GE WAN standard, or any other SONET-based standard, for use in creating networks. This results in an increase of capacity, a better price/performance ratio, and a system that is easier to use and operate.  
     
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       [0035]     A better understanding of the invention can be obtained from the following detailed description of one exemplary embodiment as considered in conjunction with the following drawings in which:  
         [0036]      FIG. 1   a  is a block diagram depicting a transport system connecting multiple LANs according to the prior art POS approach;  
         [0037]      FIG. 1   b  is a block diagram depicting a transport system connecting multiple LANs according to the ATM approach;  
         [0038]      FIG. 2   a  is a block diagram depicting a transport system connecting multiple LANs according to the present invention in a layer  3  router approach;  
         [0039]      FIG. 2   b  is a block diagram depicting a transport system connecting multiple LANs according to the present invention in a layer  2  switch approach;  
         [0040]      FIG. 3  is a block diagram of the 10GE LAN transceiver according to the present invention;  
         [0041]      FIG. 4  is a block diagram depicting a LOM according to the present invention;  
         [0042]      FIG. 5  is a block diagram depicting two variations of transport systems serially connected to one another according to the present invention; and  
         [0043]      FIG. 6  is a block diagram depicting a 10GE LAN regenerator according to the present invention.  
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0044]     In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness. Reference of an A-Z signal or direction means from the left side of the drawing to the right side of the drawing while Z-A means from the right side to the left side. The A-Z or Z-A designation is used for illustrative purposes only.  
         [0045]      FIG. 1  illustrates the block diagram of a transport system interconnecting multiple LANs according to the prior art.  FIG. 1  illustrates two different typical prior art approaches: The POS approach ( FIG. 1   a ) and the ATM approach ( FIG. 1   b ). In both approaches, the transport system  100  is connected at both ends by OC192 SONET transceivers  110   a ,  110   b ,  110   y  and  110   z.    
         [0046]     For the POS approach in  FIG. 1   a , Ethernet-based secondary systems  101   a - f  are connected to Ethernet switches  104   a  and  104   b  via Ethernet signals  121 . Ethernet signals  121  may be 10 Mb, 100 Mb, or 1 Gb and are based on the IEEE 802.3 standard, herein incorporated by reference. Switches  104   a  and  104   b  are connected to router  106   a  via 10GE LAN signals  122 . Router  106   a  is connected to transceiver  110   a  via OC192 SONET POS signal  120   a . Transceiver  110   a  is connected to transport system  100 . Transport system  100  is connected to transceiver  100   y . Transceiver  100   y  is connected to router  106   z  via POS signal  120   b . Router  106   z  is connected to switches  104   y  and  104   z  via 10GE LAN signals  122 . Switches  104   y  and  104   z  are connected to Ethernet-based secondary systems  102   a - f  via Ethernet signals  121 .  
         [0047]     The communications to and from secondary systems  101   a - f  through switches  104   a  and  104   b  and to router  106   a  occurs via Ethernet packets. To communicate over transport system  100 , router  106   a  converts the standard Ethernet LAN packets existing on 10GE LAN signals  122  to POS signal  120   a . The POS signal  120   a  frame format differs in form from the standard 10GE LAN signal  122  frame format and conversion is required from one to the other. Routers  106   a  and  106   z  communicate over POS signal  120   a  and  120   b  in a point-to-point fashion utilizing the POS protocol. The transceivers  110   a  and  110   y  at either end of the transport system  100  do not participate at the POS protocol level with the routers  106   a  and  106   z  and therefore the routers  106   a  and  106   z  appear to each other as if they are directly connected.  
         [0048]     For the ATM approach in  FIG. 1   b , Ethernet-based secondary systems  103   a - 1  are connected to switches  104   c - f  via Ethernet signals  121 . Switches  104   c - f  are connected to routers  106   b - e  via 10GE LAN signals  122 . Routers  106   b - e  are connected to ATM Switches  118   a  and  118   b  via OC48 ATM signals  124 . ATM Switches  118   a  and  118   b  are connected to SONET Add/Drop Multiplexers (ADM)  112   a  and  112   b  via ATM signals  124 . SONET ADMs  112   a  and  112   b  are connected to a SONET Broadband Cross-connect (BXC)  113   a  via an OC192 SONET ring  126   a . BXC  113   a  is connected to transceiver  110   b  via an OC192 SONET TDM signal  123   a . Transceiver  110   b  is connected to transport system  100 . Transport system is connected to transceiver  110   z . Transceiver  110   z  is connected to BXC  113   z  via TDM signal  123   b . BXC  113   z  is connected to SONET ADMs  112   y  and  112   z  via SONET ring  126   b . SONET ADMs  112   y  and  112   z  are connected to ATM Switches  118   y  and  118   z  by ATM signals  124 . ATM switches  118   y  and  118   z  are connected to routers  106   v - y  via ATM signals  124 . Routers  106   v - y  are connected to switches  104   u - x  via 10GE LAN signals  122 . Switches  104   u - x  are connected to Ethernet-based secondary systems  104   a - 1  via Ethernet signals  121 .  
         [0049]     The communications to and from the secondary systems  103   a - 1 , Ethernet switches  104   c - f , and routers  106   b - e  occurs via Ethernet packets. To communicate over transport system  100 , routers  106   b - e  convert standard Ethernet LAN packets existing on 10GE LAN signals  122  to ATM signal  124 . The ATM signal  124  frame format  124  differs in form from the standard 10GE LAN signal  122  frame format and conversion is required from one to the other. The standard ATM signal  124  is switched via the ATM switches  118   a  and  118   b  and transported into ATM signal  124  time-slots on the SONET ring  126   a  by the ADMs  112   a  and  112   b . The ATM signal  124  time slots on the SONET ring  126   a  are removed by the BXC  113   a  and are cross-connected onto ATM signal  124  time-slots on TDM signal  123   a . TDM signal  123   a  is then placed onto transport system  100  by transceiver  110   b.    
         [0050]     Routers  106   b - e  and routers  106   v - y  can communicate with each other via standard ATM virtual circuits (VCs) that flow through the ATM switches  118   a - b  and  118   y - z  and are transported over the ADMs  112   a - b  and  112   y - z , SONET ring  126   a , BXC  113   a  and  113   z , and transceivers  110   b  and  110   z . The transceivers  110   b  and  110   z , ADMs  112   a - b  and  112   y - z , SONET rings  126   a  and  126   b , BXC  113   a  and  113   z , and TDM signal  123   a  and  123   b  do not participate at the ATM protocol level with the ATM switches  118   a ,  118   b ,  118   y  and  118   z , and therefore the ATM switches  118   a ,  118   b ,  118   y  and  118   z  appear to each other as if they are directly connected. Additionally, the ATM switches  118   a ,  118   b ,  118   y  and  188   z  do not participate in the routing protocols run on the routers  106   b - e  and  106   v - y  and thus the routers  106   b - e  and  106   v - y  also appear as if they are directly connected to each other.  
         [0051]      FIG. 2  is a block diagram depicting a transport system interconnecting multiple LANs in accordance with the present invention.  FIG. 2  illustrates two different approaches that could be utilized.  FIG. 2   a  represents the layer  3  Router approach.  FIG. 2   b  represents the Layer  2  Switch approach. In both approaches, the transport system  100  is connected to Ethernet networks by 10GE LAN transceivers  200   a - b  and  200   y - z.    
         [0052]     For the Layer  3  Router approach in  FIG. 2   a , secondary Ethernet systems  101   a - f , as shown in the prior art system of  FIG. 1   a ., are connected to switches  104   a  and  104   b  via Ethernet signals  121 . Switches  104   a  and  104   b  are connected to router  106   a  via 10GE LAN signals  122 . Router  106   a  is connected to 10GE LAN transceiver  200   a  via 10GE LAN signal  122   a . 10GE LAN transceiver  200   a  is connected to transport system  100 . Transport system  100  is connected to 10GE LAN transceiver  200   y . 10GE LAN transceiver  200   y  is connected to router  106   z  via 10GE LAN signal  122   y . Router  106   z  is connected to switches  104   y  and  104   z  via 10GE LAN signals  122 . Switches  104   y  and  104   z  are connected to secondary systems  102   a - f  via Ethernet signals  121 .  
         [0053]     The standard 10GE LAN signal  122   a  is transmitted from the router  106   a  through the 10GE LAN transceiver  200   a  continuing through the transport system  100  through the 10GE LAN transceiver  200   y  and to the router  106   z  without conversion at the frame level, thus creating an end-to-end Ethernet infrastructure. Routers  106   a  and  106   z  are capable of supporting 10GE LAN signals  122   a  and  122   y  and such an interface is well known in the art and will not be further described here. The 10GE LAN signals  122  pass from the router  106   z  to switches  104   y  and  104   z . The 10GE Ethernet LAN frame as defined in the IEEE 802.3 specification is not altered in transit through the transceiver or transport system.  
         [0054]     For the Layer  2  Switch approach in  FIG. 2   b , secondary ethernet systems  103   a - 1  are connected to switches  104   c - f  via Ethernet signals  121 . Switches  104   c - f  are connected to the Layer 2 Ethernet switch  117   a  via 10GE LAN signals  122 . Layer 2 Ethernet switch  117   a  is connected to 10GE LAN transceiver  200   b  via 10GE LAN signal  122   b . 10GE LAN transceiver  200   b  is connected to transport system  100 . Transport system  100  is connected to 10GE LAN transceiver  200   z . 10GE LAN transceiver  200   z  is connected to the Layer  2  Ethernet switch  117   z  via 10GE LAN signal  122   z . Layer  2  Ethernet switch  117   z  is connected to switches  104   u - x  via 10GE LAN signals  122 . Ethernet switches  104   u - x  are connected to secondary systems  104   a - 1  via Ethernet signals  121 . The standard 10GE LAN signal  122   b  is transmitted from the Layer 2 Ethernet switch  117   a  through the 10GE LAN transceiver  200   b , through the transport system  100  through the 10GE LAN transceiver  200   z  and to the Layer  2  Ethernet switch  117   z  without conversion at the frame level.  
         [0055]     According to the present invention, the standard 10GE LAN signal  122   a ,  122   b ,  122   y , and  122   z  are not converted to a standard SONET signal  120  prior to reception by transceivers  200   a ,  200   b ,  200   y , and  200   z . For example, the standard 10GE LAN signal  122   b  is transmitted directly from the Layer  2  Ethernet switch  117   a  through the 10GE LAN transceiver  200   b  without conversion to the standard ATM signals  124 , standard SONET ring  126   a  or SONET TDM signal  123   a  as was required in the prior art system of  FIG. 1   b . 10GE LAN transceivers  200   a ,  200   b ,  200   y , and  200   z  of  FIG. 2  receive a standard 10GE LAN signal  122   a ,  122   b ,  122   y , and  122   z , not a SONET POS signal  120   a  or a SONET TDM signal  123   a . Because conversions from the 10GE LAN signals to standard ATM signals and standard SONET ring and TDM signal are not required, ATM switches  118 , SONET ADMs  112 , and SONET BXCs  113  required by the prior art are not required in a network incorporating the present invention.  
         [0056]      FIG. 3  is a block diagram of 10GE LAN transceiver  200 . 10GE LAN transceiver  200  includes a physical medium device (PMD)  301  able to receive a 10GE LAN signal  122   a  and transmit a 10GE LAN signal  122   b . The specifications for various PMDs for the 10GE LAN standard are defined in the IEEE 802.3 specification and are well known in the art. Laser temperature, laser current (optical PMDs) and “loss of signal” information is transmitted to micro-controller  350  from PMD  301  through control line  351  to monitor the performance of PMD  301 . Also, the micro-controller  350  is able to control the PMD  301  through control line  351 .  
         [0057]     Upon receiving a 10GE LAN signal  122   a , PMD  301  converts the standard 10GE LAN signal  122   a  into a standard electrical 10GE LAN signal  308 . The electrical 10GE LAN signal  308  from PMD  301  is transmitted to an electrical de-multiplexer (De-Mux) chip  304 . Standard electrical 10GE LAN signal  308  is transmitted by the PMD  301  at the same serial data rate 10.3125 Gb/sec as the standard 10GE LAN signal  122   a  and is defined by IEEE 802.3 standard. De-Mux  304  recovers clock and data information and divides the serial standard electrical 10GE LAN signal  308  into an intermediate 16-channel wide 10GE LAN signal  326  transmitted in parallel format to the 10GE LAN media access controller (MAC) chip  312 . Status information such as bit error rate (BER) and chip identification are transmitted to micro-controller  350  from De-Mux  304  via line  352  as required to maintain optimal system performance. PMD  301  is also connected to an electrical multiplexer (Mux)  302  through serial standard 10GE LAN electrical signal  306 . Mux  302  combines an intermediate 16-channel wide 10GE LAN signal  324  transmitted from the MAC  312  into a 10GE LAN serial signal at 10.3125 Gb/sec that is transmitted to PMD  301  through line  306 . Mux  302  communicates with micro-controller  350  through line  353 , transmitting status information and chip identification codes.  
         [0058]     Transponder modules  310  that combine PMD  301 , Mux  302  and De-Mux  304  are commercially available and typically identified as 10 G Multi-Source Agreement (MSA) Transponder modules (300-pin or 200-pin), XenPak, Xpak, or XFP Transponder modules. Variations of the transponder modules  310  commercially exist to support a variety of media, optical fiber types, wavelengths, and reaches according to the IEEE 802.3 specification. An example MSA module  310  includes the Network Elements MiniPHY-300 that can be used to convert a 1310 nm optical signal to an electrical signal and convert an electrical signal to a 1310 nm optical signal. In addition, a wide variety of other commercially available transponder modules can also be implemented to accomplish this task. In the preferred embodiment, transponder module  310  may be changed before or during operation to accommodate various 10GE LAN client applications.  
         [0059]     MAC  312  provides for a standard IEEE 802.3 10GE LAN MAC implementation as specified by the IEEE 802.3 standard. MAC  312  is used as a performance-monitoring device for the intermediate 10GE LAN signals  326  and  328 . The MAC  312  monitors the packet data, idle, preamble and the remaining sections of the standard 10GE LAN signals as defined by the IEEE 802.3 standard. MAC  312  also identifies the total number of packets present, the total number of bytes present, performs cyclic redundancy checks (CRC) to detect errors in each packet, and performs numerous other packet monitoring functions as defined by the IEEE 802.3 standard. MAC  312  then communicates this performance monitoring information to micro-controller  350  via line  354 . The micro-controller  350  also uses line  354  to instruct MAC  312  to be configured in such a way that the intermediatel OGE LAN signals  326  and  328  pass through MAC  312  unmodified while the performance monitoring information is extracted. Further, micro-controller  350  is able to receive copies of 10GE LAN frames from MAC  312  via line  354 .  
         [0060]     Micro-controller  350  utilizes the performance monitoring information to report how the 10GE LAN signal is performing. In one embodiment, micro-controller  350  polls line  354  extracting the number of packet errors. If certain thresholds are crossed, then an error is reported to the management system indicating a problem exists. If the errors reach a critical level, then micro-controller  350  can shut down the 10GE LAN signals  122  to prevent promulgation of errors.  
         [0061]     The MAC  312  transmits the standard electric intermediate 10GE LAN signal  330  to the Forward Error Correction (FEC) device  314 . FEC  314  is a device known in the art and performs the function of adding or deleting redundant information to the input bit pattern to allow it to be encoded and decoded to successfully eliminate errors resulting from transmission over the transport system  100 . The FEC is not required for the functionality of the invention but is incorporated in the preferred embodiment for optimal performance. FEC  314  is in communication with Mux  318  via signal  334 . As the signal is passed from MAC  312  through FEC  314  to Mux  318 , FEC  314  adds extra data to the bit pattern contained in 10GE LAN signal  330  to allow for the recovery of potentially damaged bits in 10GE LAN signal  330  after 10GE LAN signal  330  has been transmitted over transport system  100 . FEC  314  divides 10GE LAN signal  330  into predetermined sizes or frames and adds redundant information to the frames before transmission to Mux  318  via 10GE LAN signal  334 .  
         [0062]     In the reverse direction, FEC  314  receives FEC-wrapped frames over 10GE LAN signal  332  from De-Mux  316  and utilizes the redundant FEC information to correct data errors up to the FEC algorithm&#39;s limit. If the errors exceed the algorithm&#39;s limit, FEC  314  notes that the frame&#39;s errors were unrecoverable and reports the unrecoverable frame error to micro-controller  350  through line  355 . If the FEC frame&#39;s errors are within the FEC algorithm&#39;s limit, FEC  314  corrects the frame, extracts the original 10GE LAN signal and transmits the corrected signal to MAC  312  via intermediate 10GE LAN signal  328  for further processing.  
         [0063]     Mux  318  combines the parallel signals of the 10GE LAN signal  334  into a serial clock signal  339  and a phase shifted serial data signal  338 . Mux  318  communicates statistics and chip identification codes to micro-controller  350  through line  357 . The serial clock signal  339  and serial data signal  338  are then transmitted to line optics module (LOM)  400 .  
         [0064]     LOM  400  converts the serial data signal  338  and the serial clock signal  339  into optical signal  342 . Optical signal  342  has a specific wavelength suitable for transmission over the transport system  100 . LOM  400  reports measurements on laser drive current, laser bias voltage, and other parameters to micro-controller  350  through line  358 .  
         [0065]     The above describes an A-Z signal, for a Z-A signal LOM  400  receives incoming optical signal  340  from the transport system  100 . LOM  400  converts optical signal  340  into a serial FEC-wrapped 10GE LAN electrical signal  336 . The FEC-wrapped 10GE LAN electrical signal  336  is then transmitted to De-Mux  316 . De-Mux  316  recovers clock and data information from 10GE LAN electrical signal  336  and divides the serial standard electrical 10GE LAN signal  336  into an intermediate 16-channel wide 10GE LAN signal  332  transmitted in parallel format to FEC  314 . De-Mux  316  communicates with micro-controller  350  through line  356  on the presence or absence of a usable signal and the BER of the 10GE LAN electrical signal  336 .  
         [0066]     FEC  314  performs error correction as is described above and transfers the intermediate 10GE LAN signal  328  to MAC  312 . MAC  312  monitors the performance of the intermediate 10GE LAN signal  328  as previously described and transparently passes the intermediate 10GE LAN signal  328  via signal  324  to Mux  302 . Mux  302  recombines signal  324  into a serial standard 10GE LAN electrical signal  306  that is then transmitted to the PMD  301 . PMD  301  converts the standard electrical 10GE LAN signal  306  to a standard 10GE LAN signal  122   b  as defined in the IEEE 802.3 standard, and sends standard 10GE LAN signal to router  106   a  or switch  117   a  depending on the architecture of the system.  
         [0067]      FIG. 4  is a block diagram of LOM  400  according to the present invention. In LOM  400 , in the direction of a Z-A, an optical FEC-wrapped 10GE LAN signal  340  that has been transmitted over a transport system  100  is received by photo detector  414 . Photo detector  414  converts the optical FEC-wrapped 10GE LAN signal  340  to an electrical voltage signal  412 . Voltage signal  412 , in the range of 50 milli-volts, is then transmitted to amplifier  410  where the voltage of the signal is increased to a range of 500 milli-volts. Some models of photo detectors supply adequate voltage on signal  412  so the amplifier  410  may not be required. After the voltage in signal  412  has been increased by amplifier  410 , 10GE LAN electrical signal  336  is sent from the LOM  400  to the De-Mux  316  (as shown in  FIG. 3 ).  
         [0068]     In the LOM  400 , in the direction of A-Z, serial clock signal  339  from Mux  318  is sent to a modulator driver  434 . Serial clock signal  339  may be on the order of 500 milli-volts. Also, serial data signal  338  from Mux  318  is sent to a second modulator driver  438 . Serial data signal  338  may also be on the order of 500 milli-volts.  
         [0069]     A continuous-wave laser  420  is provided to generate laser optical signal  422  with an optical power on the order of 20 milli-watts. Laser  420  is locked to a specific frequency and temperature to produce a specific wavelength on laser optical signal  422 . According to the present invention, a wavelength of 1520 to 1620 nanometers is desired with an accuracy of 0.01 nanometers. However, a wide variety of wavelengths and spectral widths can be implemented without detracting from the spirit of the invention. The laser optical signal  422  is sent to modulator  424 .  
         [0070]     In addition to receiving the laser optical signal  422 , modulator  424  also receives a clock driver signal  432  from modulator driver  434 . Clock driver signal  432  may be on the order of 12-volts. The modulator  424  modulates the laser optical signal  422  in accordance with the clock driver signal  432 . The clock-modulated optical signal  426  is then transmitted to a second modulator  428 . In addition to the clock-modulated optical signal  426 , second modulator  428  also receives a phase-shifted data input signal  436  from second modulator driver  438 . Phase-shifted data input signal  436  may be on the order of 8-volts. Second modulator  428  modulates the clock-modulated optical signal  426  a second time in accordance with phase-shifted data input signal  436 . The double-modulated optical signal  342  is then transmitted from the LOM  400  to transport system  100 . While  FIG. 4  shows the laser is externally modulated, the laser may also be internally modulated.  
         [0071]      FIGS. 5   a  and  b  are block diagrams depicting the use of the invention in two architectural approaches to extend the reach of a transport system  100 . Other architectural approaches can be utilized without detracting from the spirit of the invention.  
         [0072]     In serial transport system architecture  600 , shown in  FIG. 5   a , separate 10GE LAN transport systems  601 ,  602 , and  699  are each equipped with one or more 10GE LAN transceivers  200   a ,  200   b ,  200   y  and  200   z . The transceivers  200   a ,  200   b ,  200   y  and  200   z  are operationally connected to a combination of transport systems  100   a - z  and regenerators  500   a  and  500   b  in an alternating arrangement. The ellipsis in the drawing indicates that there could be any number of reiterations of the architecture between  602  and  699 . The overall system reach of the 10GE LAN signals is extended by serially connected adjacent 10GE LAN transceivers ( 200   a / 200   y  and  200   b / 200   z ) to form a continuous signal path for one or more 10GE LAN signals. By orientating transceivers  200   a ,  200   b ,  200   y  and  200   z  in such a manner, they act as repeaters.  
         [0073]     In the A-Z direction, 10GE LAN signal  122   a  is received by transceiver  200   a , transmitted over transport system  100   a , and received by transceiver  200   y . Transceiver  200   y  then sends 10GE LAN signal  122  to a second transceiver  200   a  to be transmitted over second transport system  100   b . By transceiver  200   y  sending 10GE LAN signal  122  to transceiver  200   a  to be transmitted over a transport system the overall system reach of the 10GE LAN signals is extended. The process of serially connecting adjacent 10GE LAN transceivers continues until the desired distance is reached. Any number of transport systems  100  can be serially interconnected with pairs of 10GE LAN transceivers  200 . Just as transceivers  200   a  and  200   y  can be serially connected to regenerators  500   a  in the A-Z direction, transceivers  200   b  and  200   z  can be serially connected to regenerators  500   b  in the Z-A direction as is shown in  FIG. 5 .  
         [0074]      FIG. 6  is a block diagram of the 10GE LAN regenerator  500 . 10GE LAN regenerator  500  is a specialized version of a 10GE LAN transceiver  200  that lacks the external client 10GE LAN signals  122   a  and  122   b . The purpose of the 10GE LAN regenerator  500  is to recover signal  504  from a transport system  100   a  and process the signal in such a way that signal  542  is suitable for retransmission on the next iteration of a transport system  100   b  (see  FIG. 5   b ). Going the opposite direction, 10GE LAN regenerator  500  could recover signal  540  from a transport system  100   b  and process the signal in such a way that signal  502  is suitable for retransmission on the next iteration of a transport system  100   a . In the preferred embodiment, 10GE LAN regenerator  500  includes LOM  400   a  that receives transport system optical signal  504 . LOM  400   a  reports measurements on laser drive current, laser bias voltage, and other parameters to micro-controller  350  through line  551 . LOM  400   a  converts transport system optical signal  504  into serial electrical 10GE LAN signal  508  and sends serial electrical 10GE LAN signal  508  to De-Mux  512 .  
         [0075]     De-Mux  512  recovers clock and data information and divides the serial electrical 10GE LAN signal  508  into an intermediate 16-channel wide 10GE LAN signal  526 . Status information such as bit error rate (BER) and chip identification are transmitted to micro-controller  350  from De-Mux  512  via line  552  as required to maintain optimal system performance. De-Mux  516  performs a similar function on a Z-A signal as De-Mux  512 . De-Mux  516  recovers clock and data information and divides the serial electrical 10GE LAN signal  536  into an intermediate 16-channel wide 10GE LAN signal  532 . De-Mux  516  is in communication with micro-controller  350  via line  556  and communicates the same type of status information as De-Mux  512 .  
         [0076]     In the A-Z direction, intermediate 10GE LAN signal  526  is communicated from De-Mux  512  to FEC  514  where the FEC algorithms recover any data that has been corrupted by the transport system  100   a . If the data errors exceed the algorithm&#39;s limit, FEC  514  notes that the frame&#39;s data was unrecoverable and reports the unrecoverable frame error to micro-controller  350  through line  554 . FEC  514  transfers the corrected signal  530  to a second FEC  515  where a new set of FEC data is calculated and added to the signal to create a second data signal  534  that incorporates the FEC data. In the Z-A direction, intermediate 10GE LAN signal  532  is communicated from De-Mux  516  to FEC  515  where the FEC algorithms recover any data that has been corrupted by the transport system  100   a . FEC  515  is in communication with micro-controller  350  through line  555  and uses line  555  to report any unrecoverable frame errors to a signal in the Z-A direction. FEC  515  transfers the corrected signal  528  to FEC  514  where a new set of FEC data is calculated and added to the signal to create a second data signal  524  that incorporates the FEC data.  
         [0077]     In the A-Z direction, data signal  534  is sent to Mux  518  and converted into serial data signal  538  and serial clock signal  539 . Mux  518  communicates statistics and chip identification codes to micro-controller  350  through line  557 . Mux  510  performs a similar function on a Z-A signal as Mux  518 . Data signal  524  is sent to Mux  510  and converted into serial data signal  506  and serial clock signal  507 . Mux  510  is in communication with micro-controller  350  via line  553  and communicates the same type of status information as Mux  518 .  
         [0078]     In the A-Z direction, data signal  538  and clock signal  539  are communicated to LOM  400   b  from Mux  518 . LOM  400   b  reports measurements on laser drive current, laser bias voltage, and other parameters to micro-controller  350  through line  558 . LOM  400   b  converts data signal  538  and clock signal  539  into transport system optical signal  542  for transport over transport system  100   b . In the Z-A direction, data signal  506  and clock signal  507  are communicated to LOM  400   a  from Mux  510 . LOM  400   a  reports measurements on laser drive current, laser bias voltage, and other parameters to micro-controller  350  through line  551 . LOM  400   a  converts data signal  506  and clock signal  507  into transport system optical signal  502  for transport over transport system  100   a.    
         [0079]     Returning to  FIG. 5   b , in serial transport system architecture  700 , separate 10GE LAN transport systems  701 ,  702 ,  703 , and  799  are each equipped with a 10GE LAN regenerator  500 . The ellipsis in the drawing indicates that there could be any number of reiterations of the architecture between 703 and 799. In architecture  700 , in the A-Z direction, 10GE LAN signal  122   a  is received by transceiver  200   a . Transceiver  200   a  transmits the signal over transport system  100   a  to 10GE LAN regenerator  500   a . 10GE LAN regenerator  500   a  and  b  may be connected together in series with the transport system  100   b  in order to form a continues signal path for one or more of the 10GE LAN signals. The overall system reach of the system is extended through multiple serially connected 10GE LAN regenerators  500   a  and  b . After the desired distance is crossed, transceiver  200   y  receives the signal from transport system  100  and pass 10GE LAN signal  122   y  to switch  117   z  as described earlier. Any number of transport systems  100  can be serially interconnected with pairs of regenerators  500   a  and  b . Just as 10GE LAN regenerators  500   a  and  b  can be serially connected in the A-Z direction, 10GE LAN regenerators  500   a  and  b  can be serially connected in the Z-A direction as is shown in  FIG. 5   b.    
         [0080]     The foregoing disclosure and description of the invention are illustrative and explanatory thereof of various changes to the size, shape, materials, components and order may be made without departing from the spirit of the invention.