Problems to hear calls on SIP trunk between CUCM v12.5 and OmniPCx

[Hashen]

Hello,
we have established a Trunk link between Cisco CUCM v12.5 and an Alcatel OmniPCx.
however we have a problem getting along on SIP trunk calls between Cisco CUCM v12.5 and Alcatel OmniPCx.
Telephones of the CP-8865 type work correctly but those of the CP-3905, CP8841, SPA514 type work randomly.

Need support, please.

[M02@rt37]

Hello @Hashen,

do you always need assistance for your request ?
Thanks.

[Hashen]

yes. 

[M02@rt37]

Hello @Hashen,

Check the SIP configuration settings on both systems, including the codecs supported and the transport protocol used for SIP signaling. Make sure the settings are compatible between the two systems.

It's possible that the CP-8865 phones are simply better suited for use with the Cisco CUCM and the SIP trunk configuration you have set up. The CP-8865 is a newer and more advanced model compared to the CP-3905 and SPA514 phones, and it may have better compatibility with SIP trunking and other advanced features.

It's important to investigate the specific error messages and logs related to the SIP trunk calls to identify the root cause of the issue and determine the best course of action to resolve it.