Monitoring datagrams in a data network

Abstract

A communication session over a network is facilitated. A signaling datagram from a source device having a source identity may be intercepted by a network device, and a response datagram may be generated for instructing the source device to send a subsequent datagram to the network device. The signaling datagram may be forwarded to a SIP server, where the SIP server associates the source identity with the network device acting on behalf of the source device, and where the SIP server operates to connect a destination device with the source device to establish a communication session over the network. The subsequent datagram may be received from the source device, and the subsequent datagram may be made available to the destination device via the network.

1 - 32 . (canceled) 
     
     
         33 . A method, performed by a network device, the method comprising:
 intercepting, by the network device, a first datagram from a source device;   forwarding, by the network device and in response to intercepting the first datagram, a response datagram to the source device, the response datagram instructing the source device to send a subsequent datagram to the network device;   receiving, by the network device, the subsequent datagram from the source device; and   forwarding, by the network device, the subsequent datagram to a destination device to establish a communication session between the source device and the destination device.   
     
     
         34 . The method of  claim 33 , where the first datagram includes a signaling datagram. 
     
     
         35 . The method of  claim 34 , where the signaling datagram comprises a Session Initiation Protocol (SIP) REGISTER request and the response datagram comprises a SIP RE-DIRECT instruction. 
     
     
         36 . The method of  claim 33 , where the subsequent datagram includes a bearer datagram. 
     
     
         37 . The method of  claim 33 , further comprising:
 forwarding, by the network device, the first datagram to a server, where the server associates the source device with the network device;   
     
     
         38 . The method of  claim 33 , further comprising:
 performing at least one of a quality-of-service (QoS) function, a traffic engineering function, a policy routing function, or a lawful intercept function on the subsequent datagram.   
     
     
         39 . The method of  claim 33 , further comprising:
 applying an application classifier, in conjunction with making the subsequent datagram available to the destination device, to implement a rule set for making decisions about signaling traffic traversing the network device.   
     
     
         40 . A network device comprising:
 a processor to:
 intercept a first datagram from a source device; 
 forward, in response to intercepting the first datagram, a response datagram to the source device, the response datagram instructing the source device to send a subsequent datagram to the network device; 
 receive the subsequent datagram from the source device; and 
 forward the subsequent datagram to a destination device to establish a communication session between the source device and the destination device. 
   
     
     
         41 . The network device of  claim 40 , where the first datagram includes a signaling datagram. 
     
     
         42 . The network device of  claim 41 , where the signaling datagram comprises a Session Initiation Protocol (SIP) REGISTER request and the response datagram comprises a SIP RE-DIRECT instruction. 
     
     
         43 . The network device of  claim 40 , where the subsequent datagram includes a bearer datagram. 
     
     
         44 . The network device of  claim 40 , where the processor is further to:
 forward the first datagram to a server, where the server associates the source device with the network device.   
     
     
         45 . The network device of  claim 40 , where the processor is further to:
 perform at least one of a quality-of-service (QoS) function, a traffic engineering function, a policy routing function, or a lawful intercept function on the subsequent datagram.   
     
     
         46 . The network device of  claim 40 , where the processor is further to:
 apply an application classifier, in conjunction with making the subsequent datagram available to the destination device, to implement a rule set for making decisions about signaling traffic traversing the network device.   
     
     
         47 . A system comprising:
 a network device comprising:
 an input interface, 
 an output interface, and 
 a processor to:
 intercept, via the input interface, a registration datagram from a source device, 
 send a redirection datagram to cause the source device to direct a subsequent datagram to the network device, 
 send registration information extracted from the registration datagram to a registrar via the output interface, the registration datagram causing the registrar to send a subsequent datagram, intended for the source device, to the network device, where the network device acts on behalf of the source device, 
 receive, via the input interface, the subsequent datagram, where the subsequent datagram includes one of bearer data or signaling data, 
 monitor the signaling data when the subsequent datagram includes the signaling data, and 
 apply quality of service monitoring to the bearer data when the subsequent datagram includes the bearer data. 
 
   
     
     
         48 . The system of  claim 47 , where the source device comprises a Session Initiation Protocol (SIP) device and the registrar comprises a SIP registrar. 
     
     
         49 . The system of  claim 47 , where, when intercepting the registration datagram, the processor is to transparently intercept the registration datagram. 
     
     
         50 . The system of  claim 47 , where the processor is further to:
 terminate the subsequent datagram; and   create a new datagram, where the new datagram includes one of bearer data or signaling data.   
     
     
         51 . The system of  claim 47 , where the processor is further to use a content addressable memory (CAM) to monitor the bearer data when the subsequent datagram includes bearer data. 
     
     
         52 . The system of  claim 47 , where the processor is further to:
 monitor one of the bearer data or the signaling data to perform one or more of traffic engineering, policy routing, or lawful intercept functions.