Validating the Via Header in INVITEs and re-INVITEs

This validation compares the top VIA header with the sender's IP in INVITEs or re-INVITEs received from NTT. The check is independent of the INVITE/re-INVITE R-URI validation described above. These request validations require that you configure only the ntt-request-valid option in the SurrogateRegister.spl, but applicable deployments typically also have all the NTT Message Converter options configured.

If you do not configure the ntt-request-valid option, there is no validation check and the ESBC simply proceeds with the call. When you configure this option and the VIA header does not match, however, the ESBC drops requests that fail this validation and does not provide any response.

The ESBC identifies the sender's IP as follows:

• You have configured the sender's session-agent with static IP.
• The hostname for this session-agent is configured in the registerHost parameter in the surrogate-agent.

Consider the example configuration:

• You have configured the register-host parameter on the applicable surrogate-agent to the value "ipvoice.jp".
• You have configured the hostname parameter on the applicable session-agent to the value "ipvoice.jp", and the ip-address parameter to 10.180.111.1.

The ESBC identifies the session-agent using the register-host parameter of the surrogate-agent and the ip-address of that session-agent, 10.180.111.1, as the sender's address.

Note:

For NTT deployments, this sender's address is often called "NTT". which is typically a single surrogate-agent.