Abstract:
A system and method for communicating alarms. Packets are communicated through multiple maintenance entities in one or more networks. A determination is made that there is a failure between or at one of the multiple maintenance entities in the one or more networks. An alarm is generated at a maintenance entity nearest the failure in response to determining there is a failure. The alarm indicates a location of the failure and an identification of a communications service provider associated with the failure. The alarm is communicated back through one or more of the multiple maintenance entities to a maintenance end point. The alarm is routed to at least a communications service provider determined to be associated with the failure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation of U.S. patent application Ser. No. 13/094,433 filed on Apr. 26, 2011 entitled SYSTEM AND METHOD FOR COMMUNICATING ALARMS BETWEEN DEVICES OF A PACKET NETWORK which is a Continuation application of U.S. patent application Ser. No. 12/323,804 filed on Nov. 26, 2008, now U.S. Pat. No. 7,957,299 entitled SYSTEM AND METHOD FOR TRACKING ALARMS IN A PACKET NETWORK which claims priority to U.S. Provisional Patent Application Ser. No. 61/082,138, filed on Jul. 18, 2008. The entire contents of which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The Ethernet protocol is rapidly growing as a communications protocol between different service providers. The T1 standard is reliable because there is a known bit rate and if there are deviations, performance problems are easily verified using the end points and loop around functions, the T1 protocol may also use an alarm indicator signal or state that may be passed to every circuit path segment from end to end to indicate far end and near end fault detection. Because Ethernet protocol is non-synchronous, determining or communicating performance statistics and alarms for each segment of a connection or specific devices may be difficult. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    One embodiment provides a system, method, and maintenance entity for communicating alarms. Packets are communicated through multiple maintenance entities in one or more networks. A determination is made that there is a failure between or at one of the multiple maintenance entities in the one or more networks. An alarm is generated at a maintenance entity nearest the failure in response to determining there is a failure. The alarm indicates a location of the failure and an identification of a communications service provider associated with the failure. The alarm is communicated back through one or more of the multiple maintenance entities to a maintenance end point. The alarm is routed to at least a communications service provider determined to be associated with the failure. 
         [0004]    Another embodiment provides a system for communicating alarms. The system may include a one or more networks for communicating packets. The system may also include a multiple maintenance entities. Each of the multiple maintenance entities is operable to determine there is a failure between or at one of the plurality of maintenance entities, generate an alarm at a maintenance entity nearest the failure in response to determining there is a failure, the alarm indicates a location of the failure and an identification of a communications service provider associated with the failure, and communicate the alarm indicating the location of the failure and the identification of the communications service provider back through one or more of the multiple maintenance entities to a maintenance end point. The alarm is routed at least two a communications service provider determined to be associated with the failure. 
         [0005]    Another embodiment provides a maintenance entity. The maintenance entity may include a processor for executing a set of instructions and a memory operable to store the set of instructions. The set of instructions may be executed to communicate packets as part of a communications path, the communications path may include multiple maintenance entities, determine there is a failure at maintenance entities in direct communication with the maintenance entity or between the maintenance entities and the maintenance entity; generate an alarm at the maintenance entity in response to determining there is a failure, the alarm may indicate a location of the failure and an identification of a communications service provider associated with the service provider; and communicate the alarm back through one or more of the plurality of maintenance entities to a maintenance end point, wherein the alarm is routed at least two a communications service provider determined to be associated with the failure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein: 
           [0007]      FIG. 1  is a pictorial representation of a communications environment in accordance with an illustrative embodiment; and 
           [0008]      FIG. 2  is a flowchart of a process for detecting network problems in accordance with an illustrative embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0009]    One or more of the illustrative embodiments provide a system and method for sending an alarm indicator signal (AIS) from one maintenance entity (ME) operation administration and maintenance (OAM) group to another to communicate the location and type of a fault. In one embodiment, the illustrative embodiments may be implemented for a metro Ethernet network (MEN). The AIS is a coded signal that is sent to network devices and elements to indicate a problem state or that a failure has been detected and an alarm generated. The AIS may be passed from one ME to another using domain state stitching or associating the AIS states of two or more ME or OAM levels so that the AIS signal from one ME may be communicated to the associated ME via a coded signal. One embodiment of the coded signal is a time length value (TLV) field of the Ethernet OAM protocols. State sharing or stitching may occur across multiple ME domains whereby an AIS signal from a distant customer or provider may be communicated over multiple service provider ME domains to the far end which may be owned by the customer or provider. As a result, the originating AIS state may be passed back to the customer or provider for fault isolation. 
         [0010]    The location of the problem, issue, or failure may be determined based on the end-point or ME that generated the original AIS. For example, the next in a chain of MEs may be determined to be the failure point. One or more of the illustrative embodiments may provide a protocol for ensuring that the appropriate service provider is contacted to diagnose and fix a problem rather than requiring any number of functioning service providers to unnecessarily troubleshoot their individual systems. As a result, any number of customers or service providers may be able to determine a point of origination or location of performance issues and alarms in one or more networks. 
         [0011]    A user-to-network (UNI) network is the physical and electrical demarcation point between the user and the public network service provider, typically a MEN and customer premises equipment. Typically, any layer 2 maintenance entity or maintenance association includes two or more end points, generally referred to as maintenance end points (MEP). AIS are alerts that provide information regarding information, such as performance and state of ports, layer 2 paths, operational status, and network element status. For example, the AIS may indicate there is no power throughout the MEN. Illustrative embodiments provide an efficient system for passing AIS between groups of MEs or specific domains. The AIS indication itself may be augmented with other TLV data to identify the type or location of an ME triggering an alarm based on a problem. 
         [0012]      FIG. 1  is a pictorial representation of a communications environment in accordance with an illustrative embodiment.  FIG. 1  illustrates one embodiment of a communications environment  100 . The communications environment  100  is the devices, equipment, and systems for enabling communications. In particular, the communications environment may be one or more MENs and systems. The communications environment  100  may include any number of devices, equipment, systems, elements, and components. In one embodiment, the communications environment  100  may include segments  102 ,  104 ,  106 ,  108 , and  110 , a MEN  112 , ME  114 ,  116 ,  118 ,  120 , and  122 , and alarm  124 . 
         [0013]    The communications environment  100  and the MEN  112  may include various MEs  114 ,  116 ,  118 ,  120 , and  122 , MEP, service network interfaces (SNI), network interface devices, Ethernet to External Network to Network Interface (E-NNI), and other elements as described in the patent application herein incorporated. Communications may occur between any number of entities, including the MEs  114 ,  116 ,  118 ,  120 , and  122  and may communicate with the MEN  112  in any number of configurations. Alternatively, the MEs  114 ,  116 ,  118 ,  120  and  122  may be considered part of the MEN  112 . In one embodiment, an SNI may be connected to the MEN  112  and may perform conversion of transmission protocols and standards, such as from Ethernet to synchronous optical network (SONET). In another embodiment, a UNI may be connected directly to the MEN  112 . In yet another embodiment, the user may connect to the MEN  112  or to another portion of the communications environment  100  through one or more service providers, segments, or territories. 
         [0014]    The segments  102 ,  104 ,  106 ,  108 , and  110  are portions of the communications environment  100  and may represent communications paths and routes utilized for data communications. The segments  102 ,  104 ,  106 ,  108 , and  110  may be operated by one or more communications service providers, users, entities, or other operators. Each segment  102 ,  104 ,  106 ,  108 , and  110  may include multiple nodes, domains, entities, devices, systems, equipment, controllers, connections, and other communications elements. The segments  102 ,  104 ,  106 ,  108 , and  110  may also represent ME domains/pairs. 
         [0015]    In one embodiment, the domains or entities of the communications environment  100  may include the MEN level of the service provider, an access segment outside of the ME, and a customer UNI ME. In another embodiment, the communications environment  100  may only include two segments, such as connections between the customer, a local service provider, and the access service provider. In one embodiment, each of the segments  102 ,  104 ,  106 ,  108 , and  110  may operate without knowledge of the other segments  102 ,  104 ,  106 ,  108 , and  110 . 
         [0016]    The illustrative embodiments may allow the MEs to send AIS or alarm  124  based on failures or problems at or between the MEs  114 ,  116 ,  118 ,  120 ,  122 . In one embodiment, the ME  118  has failed. The AIS may allow one or more parties to determine which ME or segment is or has failed or is experiencing or has experienced problems. For example, the ME  116  may communicate with the applicable MEP which may be ME  114  indicating that the failure has occurred at ME  118  or the connection between ME  116  and  188 . On the other side, the ME  120  may similarly notify the ME  122  from the other communications direction. 
         [0017]    In another example a first ME pair includes MEs  116  and  120 , with a second ME pair including MEs  120  and  122 . If a power outage were to occur in ME  122  the second ME pair may indicate a failure of the layer two path and that the second ME pair may then trigger an AIS indication. The AIS indication may or may not contain the cause of the AIS failure. When the two AIS states of the first ME pair and second ME pair are “stitched” or shared, the AIS indication at ME  120  may be conveyed to the first ME pair which may then propagate the AIS conditional alarm with the originating ME pair identification to ME  116 . 
         [0018]    The failure determination may be triggered by the OAM performance threshold criteria or by traditional port state operational measurements, such as “LOS” for loss of signal. MEs  114 ,  116 ,  118 ,  120 ,  122  may communicate information via a TLV field. The illustrative embodiments may provide a signaling protocol and method for passing the AIS state of one ME to another. If both MEs terminate in the same node, the AIS state may be associated from one ME to the other ME via standard operational measures reading and state information. For example, the AIS may be generated by the ME  116  and may be communicated to one or more other domains, entities, or back to the ME  114  and MEN  112 . The AIS may be a special state alarm that uses a special frame to alarm the AIS condition. For example, a remote defect indicator (RDI) may communicate faults to an MEP at a far end. In one embodiment, the AIS and remote defect indicator packets of the illustrative embodiments may utilize standards, recommendations, or protocols, such as ITU-T Recommendation Y.1731 (05/2006). One or more of the illustrative embodiments may allow an AIS signal to be sent downstream to the other end indicating that the ME  118 , access connection, UNI port, or other network element has a failure or error. For example, if a customer experiences a power outage, the ME  116  sends the alarm  124  to the other end of the communications environment indicating that there is a power outage or other problem at the ME  118 . The AIS may be utilized to report the state at each end of an ME and the RDI may communicate the state and AIS inside of an ME segment or pair. Both types of state information may be stitched together. 
         [0019]    The alarm  124  may be any number of signals and alarm types. In one embodiment, a UNI directional frame loss alarm may indicate that data is destined for the ME  120 , but is not being received properly by the ME  120 . A continuity check packet alarm may indicate that the ME  120  or MEP is unable to hear or verify the presence or status of the far end which may include the ME  114  or the MEN  112 . The illustrative embodiment allows a problem to be identified between any number of coupled MEs. It is important to note that both point-to-point and multipoint-to-multipoint AIS alarm indications may be passed between respective yet different ME types. TLV field characterizations may indicate where the fault or alarm originated. 
         [0020]    In one embodiment, the AIS may not diagnose the error or failure, but rather may locate the failure connection, node, or point. As a result, the proper service provider, operator, or customer may be alerted right away once an AIS is activated and sent back downstream. As a result, service providers may correctly identify the location of the problem to prevent the unnecessary use of resources. In one embodiment, MEP servers utilize notification engines, such as simple network management protocol (SNMP) to notify the appropriate service provider of the alarm and a suggested corrective action. For example, the ME  116  and corresponding connection to the ME  114  may not be tested for faults or problems when ME  118  has already been identified as failing due to loss of power. In one or more of the illustrative embodiments, an AIS, once generated, is passed or flipped from the last functioning ME to another back to the MEP. For example, the ME  120  may communicate the AIS back to the ME  122  which may be a MEP. In particular, the AIS may be passed to endpoints within the communications environment ensuring that fault location information may be retrieved from the endpoint devices. In another embodiment, the AIS fault or problem location may also be retrieved from the intermediary MEs, nodes, domains, entities, or other parts of the communications environment  100 . AIS stitching may be utilized between associated MEs within the communications environment  100 . 
         [0021]      FIG. 2  is a flowchart of a process for detecting network problems in accordance with an illustrative embodiment. The process may be implemented by one or more MEs within a metro Ethernet environment, system, or network. The process may begin by detecting a problem (step  202 ). The problem may be a problem, failure, or other issue that affects communications at or between MEPs within a MEN. In one embodiment, the problem may be detected by a functioning ME that determines a subsequent ME or data connection is unavailable. 
         [0022]    Next, the ME identifies the location of the problem (step  204 ). The location may be identified utilizing a network identifier for a device, connection, or network segment. The network identifier may be a provider name, circuit identifier, ME association, MEP address, IP address, MAC address, assigned identifier, numeric sequence, or other information indicating the location of the device or connection that is experiencing the problem. As previously described, the last functioning ME in a series of MEs, domains, entities, or nodes may note the location. The network identifier may indicate the point at which packets or data are no longer able to proceed to the next ME, domain, or point. For example, by using AIS stitching between MEs, a fault may be more specifically identified, such as identifying frame loss that is occurring on the receive side of an ME and the identity of the last functioning ME. 
         [0023]    Next, the ME generates an alarm indicating a location of the problem (step  206 ). The alarm or AIS may indicate the location of the problem utilizing the identifier or other information. The ME sends the alarm signal to the MEPs (step  208 ). The alarm signal may also be retrieved, read, or analyzed by any number of intermediary MEs operated by one or more communications service providers. In one embodiment, ME associations may be paired and multiple service providers may use sharing standards or protocols for sharing AIS or RDI signals between ME domains. As a result, each service provider may know where the problem is occurring so that actions, such as troubleshooting, dispatching technicians, or other similar steps may be taken by the service provider experiencing the failure. A network identifier or ME identification may indicate where the problem or failure is from one or more sides or perspectives of the network including near and a far end identification. In one embodiment, the alarms may be color coded or numbered errors that identify the error, failure, problem, or issue. The AIS may also specify the problem category. The categories may include physical, Ethernet first mile, operational administration measurement (OAM) and other categories for bad packets, level of service (LOS), loss of signal, power loss, packet loss, fragmented packets, frame loss ratio (FLR), delay, TLV (i.e., circuit ID), or state (in-service, out-of-service). 
         [0024]    In one embodiment, performance metrics may not be necessary even though one or more of the illustrative embodiments may be implemented with a system that performs stitching for performance metrics. One or more of the illustrative embodiments may allow one or more MEs to generate or receive an alarm with the alarm state and identify the location of the alarm. One or more of the illustrative embodiments allows a communications service provider or operator to determine whether the source of the problem originates within equipment, systems devices, or connections managed by the service provider or whether the source of the problem is with a different provider/customer. 
         [0025]    The previous detailed description is of a small number of embodiments for implementing the invention and is not intended to be limiting in scope. One of skill in this art will immediately envisage the methods and variations used to implement this invention in other areas than those described in detail. The following claims set forth a number of the embodiments of the invention disclosed with greater particularity.