Patent Publication Number: US-7587758-B2

Title: Systems and methods for distributing data packets over a communication network

Description:
RELATED APPLICATION 
   This application is a continuation of and claims priority benefit under 35 U.S.C. § 120 from U.S. patent application Ser. No. 10/676,174, filed Oct. 2, 2003, which is hereby incorporated herein by reference in its entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to routing voice/video/data communications through network firewalls, and more particularly to such routing through determined network ports with minimal security risk. 
   2. Description of the Related Art 
   Heretofore, security firewalls interfered with smooth exchange of voice/video/data information over communication networks such as the internet. This difficulty could be overcome by temporarily reducing or removing firewall protection. Firewalls are established and maintained by residual local software and hardware to prevent unauthorized entry into the host system and unauthorized access to host hardware, software, database, and other resources. They are typically provided between a host computer (endpoint unit) and the outside world, especially the internet. However, firewalls may also be within a LAN (local area network) between a protected host database and intra-organizational other departments of a host organization. Without firewalls, casual hackers and other intruders may enter the host by various means including uncovering a password and logging-in as a legitimate user, Trojan Horse tactics, e-mail techniques, an open port, and other low-level strategies. Understandably, serious organizations are reluctant to reduce firewall security. 
   Instead of reducing firewall protection, costly standard based communication tools such as routers and servers were installed to support a smooth internet exchange. Standard based communication tools were selected from a pool of twenty or so commonly used, commercially available, compatible software and hardware, which fully comply with industry standard header configurations. Typical users had several of these standard based endpoint units residing locally on their host systems. These standard based units were used in conjunction with standard aware software and hardware, which merely recognizes the industry standard for controlling the flow of data packets and operating the standard based endpoint units. Currently the three major standard ITU (international telecommunication union) configurations are H323, SIP, and T120. Voice and videos units generally include programs based on H323 or and SIP. Data transfer units (white board applications, file transfers, etc.), are generally T120 based. Each configuration is subject to a particular header protocol of delivery and communication rules and procedures. 
   Users on either side of the firewall(s) needed compatible, standard based-equipment, which is typically complex, requiring an on-site, network security administrator to set-up and maintain. The firewall router were be located at any entry point into the protected LAN such as before first server, before the front end router, or before the modem end router. The desired seamless communication requires multiple firewall ports in the firewall which are serially opened one at a time. The data packet stream forms a communication which crosses the firewall through a series of different ports. For security reasons, each next-to-open-port in the series is selected at random from an available port population of 65,511 out of a total port population of 65,535. The number of ports is defined by the standard based operating system. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of this invention to provide a standard based firewall adapter for a communication system between a send endpoint(s) and a receiving endpoint(s). This standard based firewall adapter has computer hardware and software which permit multiplexed tunneling at a specified port. The adapter is compatible with older firewalls and the newer standard aware firewalls; The adapter is also compatible with older endpoint units and standard based endpoint units. The endpoint client may continue to use older user friendly, off-the-shelf, low priced hardware and software, after installing the standard based firewall adapter. Neither the send client nor the receiving client needs to install any new costly standard based components or software or review any new operating manuals for complex standard based routers and servers. An expensive upgrade to a standard based system is not required. 
   It is another object of this invention to provide such a standard based firewall adapter which is “portable”, having universal application with various operating systems. The send party&#39;s endpoint computer and endpoint operating system may be different from the receiving party&#39;s computer and operating system, and even incompatible therewith. The firewall adapter functions as an adapter or buffer between the endpoint client and the network. The endpoint sees the adapter as a fully compatible interface with the network; and the network sees the adapter as a standard based endpoint. This isolation between the endpoint and the network minimizes interface problems with routers etc. The buffer feature of the adapter increases compatibility between adapter even though the adapters are not identical. 
   It is another object of this invention to provide such a standard based firewall adapter which maintains high security by employing a single, determined port in a customized set-up configuration. By convention, port  80  is the default port, and is open to heavy web traffic from browsers and web servers. The adapter may open a non-default port exclusively for selected traffic, or employ a single customized set-up port. 
   It is another object of this invention to provide such a standard based adapter in which software for supporting various industry standard header configurations may be readily added or deleted. A user may easily expand the protocol stack to support additional standard based configurations and newly created configurations. The user may delete antiquated or unused configurations. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the present system and standard based firewall adapter will become apparent from the following detailed description and drawing in which: 
       FIG. 1  is a block diagram of simple communication system  10  between send station  14 S and receive station  14 R, through open port  15 P in firewall  15 W; 
       FIG. 2  is a block diagram of complex communication system  20  across communication internet  20 N employing a dedicated port between firewall  25 A and firewall  25 B through media server  20 M; 
       FIG. 3  is a block diagram of firewall adapter  34  showing the primary elements and functions thereof; 
       FIG. 4  is a block diagram of communication system  40  employing multiplexed channels Ch 1 -ChN in network port  45 P between firewall adapter  44 S and firewall adapter  48 R; and 
       FIG. 5  is a flow chart of the operation of the firewall adapter. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The table below lists the reference numerals employed in the figures, and identifies the element designated by each numeral. 
     10  Standard Based Communication System  10             10 D Data Packets  10 D     11 S Sending Ports  11 S     11 R Receiving Ports  11 R     12 S Sending Endpoint Unit  12 S     12 R Receiving Endpoint Unit  12 R     14 S Sending Firewall Adapter  14 S     14 R Receiving Firewall Adapter  14 R     15 W Send Firewall  15 W     15 P Open Port  15 P     16 S Sending Station  16 S     16 R Receiving Station  16 R       
     20  Standard Based Communication System  20             20 D Data Packets  20 D     20 N Communication Internet  20 N     20 M Media Server  20 M     22 A Endpoint Unit  22 A     22 B Endpoint Unit  22 B     24 A Firewall Adapter  24 A     24 B Firewall Adapter  24 B     25 A Firewall  25 A     25 B Firewall  25 B     26 A Communication Station  26 A     26 B Communication Station  26 B       
     31  Endpoint Ports  31   
     32  Endpoint Unit  32   
     34  Firewall Adapter  34             34 C Controller  34 C     34 D Demultiplexer  34 D     34 E Endpoint Interface  34 E     34 M Multiplexer  34 M     34 S Protocol Stacks  34 S     34 T Tunnel Interface  34 T     35 W Firewall  35 W     35 P Port  35 P       
     40  Communication System  40             44 S Firewall Adapter  44 S     44 T Tunnel Interface  44 T     44 L Component and Template Library  44 L     48 R Firewall Adapter  48 R     48 T Tunnel Interface  48 T     48 L Component and Template Library  48 L     45 P Port  45 P       
   Standard Based Firewall System ( FIG. 1 ) 
   System  10  distributes information data packets  10 D containing standard configuration headers from multiple send endpoint ports  11 S in send endpoint unit  12 S; to multiple receive endpoint ports  11 R in receive endpoint unit  12 R. The packets pass through standard based send firewall adapter  14 S (shown in detail in  FIG. 3 ), traverse at least one firewall  15 W through selected port  15 P, and pass through standard based receive firewall adapter  14 R. The firewall adapters are positioned between the endpoint units and the firewall. Standard based system  10  supports firewall friendly communication between send station  16 S and receive station  16 R, across a communication network such as an internet (shown in  FIG. 2 ). 
   The endpoint units in the send and receive stations may be simple PCs operated by individuals at a single work station, or a collection of end user PCs and other standard based communication devices. Alternatively, the endpoint units may be complex computer system(s) operated by large organizations. The endpoint units may be autonomous or may require intervention by a human agent. 
   Internet System ( FIG. 2 ) 
   System  20  distributes information data packets  20 D from endpoint unit  22 A, to endpoint unit  22 B. The packets pass through standard based firewall adapter  24 A, traverse firewall  25 A, and enter internet  20 N. The packets are processed by media server  20 M, traverse firewall  25 B, and pass through standard based firewall adapter  24 B. 
   The communication network may be an international or global internet providing electronic communication between networks and organizational computer facilities around the world such as communication stations  26 A and  26 B. In a less complex embodiment, the communication network may be a WAN (wide area network) or a narrower LAN (local area network). A typical LAN is a private network extending throughout a singe building or several building in close proximity. A WAN may connect several LANs. 
   The internet may contain media servers for providing communication functions such as NAT (network address translations). LANs frequently employ invisible private network addresses instead of regular IP address which are visible for outside access. The send party accesses the visible address at the media server, which routes (translates) the communication to the private address. The media server may be accessed by hundreds of parties simultaneously, each of which may have a firewall with a firewall adapter. 
   Standard Based Firewall Adapter ( FIG. 3 ) 
   The basic functional elements of firewall adapter  34  are shown in  FIG. 3  and described below. The method of operation is described in  FIG. 5 . 
   Tunnel Interface  34 T attends to technical matters associated with the firewall, the tunnel, and the internet. The tunnel interface opens and closes the tunnel and transports the stream of incoming and outgoing data packets across the internet. The tunnel interface opens multiple logical channels by assigning channel numbers in packet headers. 
   Adapter Controller  34 C coordinates the operation of the adapter, including logging users on/off, conference initiation, and access/security control. The controller also directs communication matters concerning call management such as call waiting, call transfer, call hold, messages, and directory database. 
   Voice/Video/Data Protocol Stack  34 S maintains a suitable inventory of header protocols. These protocols stamp the headers of outgoing packets as part of the creation process, and direct the flow of incoming packets. 
   Multiplexer  34 M reads the header configuration of outgoing packets in multiple streams of packets from multiple send endpoint ports  31  of send endpoint unit  32 . The multiplexer provides a single stream of multiplexed packets which traverse firewall  35 W through port  35 P. 
   Demultiplexer  34 D reads the header configuration of incoming packets in the single stream of received packets which has traversed the firewall from the internet. The demultiplexer provides multiple streams of demultiplexed packets for multiple endpoint ports  31 . The headers have destination instructions in the header which direct the multiplexer and demultiplexer. The packets destination may be one or more multiple receive endpoint ports in a receive endpoint unit. 
   Endpoint Interface Unit  34 E manages the voice and video and data (white board) activities of the endpoint unit. 
   Multiple Port/Channel Embodiment ( FIG. 4 ) 
   System  40  distributes information data packets from multiple send endpoint ports P 1 , P 2 , . . . Pn within send firewall adapter  44 S, to multiple receive endpoint ports P 1 , P 2 , . . . Pn within receive firewall adapter  48 R. The data packets enter tunnel interface  44 T on the multiple send ports, and leave on multiple corresponding logical channels C 1 , C 2 , . . . Cn. The port to channel conversion is effected by CTL (component and template library)  44 L within the tunnel interface. CTL  44 L assigns a unique channel number to the headers of the outgoing data packets arriving from each send port. All of the assigned channels are tunneled to receive firewall adapter  48 R in common network port  45 P, which is typically port  80 . CTL  48 L within tunnel interface  48 T reconverts the logical channels back into the original endpoint ports P 1 , P 2 , . . . Pn. During connection establishment, CTL  48 L directs tunnel interface  48 T to assign the original port numbers to the headers of the incoming data packets from each channel. 
   Method of Firewall Friendly Operation ( FIG. 5 ) 
   The primary steps of the general method of distributing information packets containing headers over a communication network is shown in the flow chart of  FIG. 5  and described below. The apparatus employed in carrying out the method is disclosed in  FIGS. 1-4 , and in the related detailed descriptions. The packets may originate from one or more multiple send endpoint ports, in a send endpoint unit. The packets pass through a standard based send firewall adapter, across at least one firewall, and through a standard based receive firewall adapter. In the embodiment of  FIG. 1 , system  10  has a single firewall between the communication network and either the send firewall adapter or the receive firewall adapter. In the embodiment of  FIG. 2 , system  20  has multiple firewalls between the communication network and the multiple firewall adapters. 
   Determining a single firewall port through the at least one firewall, from a plurality of firewall ports into the network. This open port may be port  80  which is normally open for public interface. Any other port may be employ as the open port. More than one port may be opened simultaneously to improve communication capacity. However, minimizing the number of open ports reduces the security risk. 
   Opening a network tunnel connection over the communication network, along determined firewall port, which connection traverses the at least one firewall. Tunneling is bidirectional. The receiving party may transmit send communications to the send party through the same open port in the firewall. 
   Multiplexing multiple streams of packets in the multiple send endpoint ports of the send endpoint unit, into the single determined firewall port, to form a single stream of multiplexed packets. 
   Sending the multiplexed packets over communication network through the opened tunnel connection, from the send firewall adapter to the receive firewall adapter. 
   Demultiplexing the single determined firewall port into the multiple receive endpoint ports of the receive endpoint unit to form multiple streams of demultiplexed packets. 
   Protocol Stacks 
   The method of distributing information packets may include the follow additional steps. 
   Providing a header protocol from a stack of protocols in response to the packet headers. 
   Altering the protocol stack by adding or deleting specific protocols. The altering is accomplished by entering or erasing codes into the protocol stack (as indicated in  FIG. 3 ). A user may easily update specific installed protocols, or expand the protocol stack inventory to support additional standard based configurations in current use. The user may upgrade the inventory to include any newly created configurations. Alternatively, the user may delete antiquated or unused configurations. 
   Firewall Port Determination 
   The determined firewall port may be selected by the send firewall adapter. The determined firewall port may be selected from a range of firewall ports. The determined firewall port may be a predetermined firewall port for supporting customized applications or special protocols. The predetermined port may be a default port such as port  80  in a HTTP (hypertext transfer protocol) application. Port  80  is a standard start/browsing port which carries active linking between pages and text, text coding, and tags for hot links. Overuse of port  80  may crowd the traffic and load the port bandwidth limitations, causing loss of data through “roll-off”. The parties may select another port which has less traffic. This selection may be executed automatically by the host computer as traffic density approaches a specified load. 
   Multiple Ports/Channels 
   The method of distributing information packets may include the follow additional steps. 
   Opening multiple logical communication channels before the sending step, corresponding to the multiple send endpoint ports. The channels are opened within the opened tunnel connection by assigning channel numbers in the header of the packets. 
   Opening multiple receive endpoint Ports after the sending step, corresponding with the multiple logical communication channels. The ports are opened within the receive endpoint unit by assigning port numbers in the header of the packets. 
   Voice/Video Over TCP Embodiment 
   Each communication network has a network protocol for distributing information packets, which may include the network protocol TCP for carrying voice and/or video data. The two primary network communication protocols for transporting information packets are UDP (user datagram protocol) and TCP (transport control protocol). 
   The UDP network protocol does not guarantee the arrival of each information packet and is therefore usually faster than the TCP protocol. UPD does not send back a return acknowledgment message of the arrival of each packet received. If a packet is misrouted due a flawed or misread header, that packet is never received; and neither the receiver or the sender are ever aware of the missing packet. These non-received packets are “lost”. Perhaps as many as 5-10% of these UPD packets become lost. The lost packets cause an anomaly or “blip” in the data stream. At low loss levels, audio/visual blimps may be accommodated by the inherent redundancy in voice/video communication. A packet may contain only a syllable, or a fraction of a word, or part of a scanline. Therefore, voice/video is commonly transported by the fast, but imperfect UDP. 
   TCP, on the other hand, does send a return message acknowledging each packet that has arrived. The sender becomes aware of which packets did not arrive by the absence of return messages; and sends a replacement packet. This non-acknowledgement, resend process continues until all of the packets have been accounted for. Unlike UPD, in TCP a packet is never lost. However, occasionally a resent packet may arrive too late to fit into the real time flow of a voice/video communication stream. The header configurations in each packet are serialized by time stamping to define a coherent data stream from the sender. When the packets are reassembled into this data stream by the receiver, some of the resent packets may not have arrived yet. These resent TCP packets are not lost, they are simply delayed and no longer useable. Such out-of-order tardiness is rare in TCP. Voice/video information sent by TCP is of higher quality than UPD. 
   INDUSTRIAL APPLICABILITY 
   It will be apparent to those skilled in the art that the objects of this invention have been achieved as described hereinbefore. Various changes may be made in the structure and embodiments shown herein without departing from the concept of the invention. Further, features of embodiments shown in various figures may be employed in combination with embodiments shown in other figures. In addition, the features of this invention may be incorporated into a suitable computer readable media which stores computer instructions for causing a computer to execute the steps of the invention. 
   Therefore, the scope of the invention is to be determined by the terminology of the following claims and the legal equivalents thereof.