Transmit to network for call processing

Last Updated : Oct 22, 2018 |

The SIP routing system finally routes the call to the target endpoint by using the connection information determined during the routing phase.

Note:

The SIP routing system retries the call to an alternate target destination where the endpoint can be reached when it receives:

  • SIP 408 response from the transaction layer.

  • SIP 5xx error response from the network.

The alternate target destination can be an IP address from the Next Hop Server 2 field of the routing profile/pending DNS NAPTR/SRV/A record entries. These entries are yet to be tried if RFC 3263 procedures are used.

The SIP routing system routes all messages including the SIP responses and the in-dialog requests and responses . For routing, the SIP routing system uses the same subscriber and server flows that were matched during the initial INVITE call processing.