Why does the Nokia N80 Internet Edition fail registration after receiving a “200 OK” response from the registrar?
• A common reason for a registration failure is that the registrar or, for example, the SIP application layer gateway (SIP-ALG) on the route modifies the Contact URI of the response. If the Contact URI does not match the original value in the REGISTER request, that is, if it is modified, the Nokia N80 Internet Edition checks if the hostname part matches the address in the received parameter of the Via header and the rport value. If these do not match, or if any URI parameter, such as transport=UDP, is removed or changed, the registration is treated as failed. According to Nokia’s interpretation of the SIP RFC 3261, the registrar shall not modify the Contact URI sent in the response to the register request. When forwarding a request, for example, INVITE, some SIP servers write their own address to the Contact URI, instead of correctly inserting a Record-Route header. This also works with the Nokia N80 Internet Edition, but as for the REGISTER request the Contact has a different meaning
Related Questions
- What happens if the Nokia N80 Internet Edition leaves the coverage of the access point for a short period of time?
- Why does the Nokia N80 Internet Edition fail registration after receiving a "200 OK" response from the registrar?
- How can it be determined which network elements work with the Nokia N80 Internet Edition?
