Viewing SIP Counters and Channels

The SIP SG Counters reflect the SIP messages sent/received at the Signalling group level. They are modeled based on the SIP RFC 3261. The request messages and its responses are incremented on send/receive directions. These counters are used mainly to troubleshoot issues and isolate failures.

SIP Counters

SIP SG Counters: Sample SIP

Request Message Counters

SIP requests or methods are considered "verbs" in the protocol, since they request a specific action to be taken by another user agent or server. The INVITE, REGISTER, BYE, ACK, CANCEL, and OPTIONS methods are the original six methods in SIP. The REFER, SUBSCRIBE, NOTIFY, MESSAGE, UPDATE, INFO, and PRACK methods are described in separate RFCs. The call-flow counters in general give a broader view of the system to help identify high-level trends or see a systematic problem.

Response Message Counters

There are six classes of SIP responses. The first five classes were borrowed from HTTP, the sixth was created for SIP.

• 1xx: Informational, Indicates status of call prior to completion. If first informational or provisional response.
• 2xx: Success, Request has succeeded. If for an INVITE, ACK should be sent; otherwise, stop retransmissions of request.
• 3xx: Redirection, Server has returned possible locations. The client should retry request at another server.
• 4xx: Client error, The request has failed due to an error by the client. The client may retry the request if reformulated according to response.
• 5xx: Server failure, The request has failed due to an error by the server. The request may be retried at another server.
• 6xx: Global failure, The request has failed. The request should not be tried again at this or other servers.

For more information see RFC 3261.

A SIP response is a message generated by a UAS or a SIP server to reply to a request generated by a UAC. A response may contain additional header fields containing information needed by the UAC. Or, it may be a simple acknowledgment to prevent retransmissions of the request by the UAC. Many responses direct the UAC to take specific additional steps.

Responses counters can be helpful as a tool for developers and service engineers to identify high-level service affecting trends. It gives a broader view of the system in terms of call-flow specifics.

Transaction Counters

SIP transactions occur between a UAC and a UAS. A SIP transaction comprises all messages from the first request sent from the UAC to the UAS up to a final response (non-1xx) sent from the UAS to the UAC.

Transaction counters can be helpful as a tool for developers and service engineers to identify high-level service affecting trends. It gives a broader view of the system in terms of call-flow specifics.

Call Counters

• Current Calls: Number of con-concurrent calls, both Inbound and Outbound, incremented on the start of Client/Server CallSession transactions.
• Total Calls: Total Number of completed and attempted calls. Incremented on the start of Client/Server CallSession transaction.;
• Connected Calls: Number of Accepted calls, usually incremented by receiving 200OK Response message.
• Refused Calls: Number of calls that were not accepted by Sonus SBC 1000/2000, incremented on receiving Response codes greater than 400 and CCNak.
• Errored Calls: Number of calls that resulted in an error, incremented on unexpected conditions that result in the call state to change to CallStateTerminated.
• Blocked Calls: This has not been defined yet.
• Egress Call Attempts: Number of outbound call attempts, incremented on start of Client transaction by UAC on Sonus SBC 1000/2000.
• Egress Calls Accepted: Number of outbound calls accepted, incremented on 200OK from UAS.
• Egress Calls Completed: Number of outbound calls completed, incremented on transaction state change to completed.
• Egress Calls Rejected: Number of outbound calls that were not accepted by Sonus SBC 1000/2000, incremented on receiving Response codes greater than 400 and CCNak.
• Ingress Call Attempts: Number of inbound calls accepted, incremented on start of Server transaction by UAS on Sonus SBC 1000/2000.
• Ingress Calls Accepted: Number of inbound calls accepted, incremented on 200OK from UAC.
• Ingress Calls Completed: Number of inbound calls completed, incremented on transaction state change to completed.
• IngressCalls Rejected: Number of inbound calls that were not accepted by Sonus SBC 1000/2000, incremented on receiving Response codes greater than 400 and CCNak.

Channel Table: SG #1