Cube config sip trunk to Deutsche Telekom

[ajber]

Does anyone have a cube config with sip trunk to Deutsche Telekom?

I have a manual from https://www.cisco.com/c/dam/en/us/solutions/collateral/enterprise/interoperability-portal/connecting-unified-communication-manager.pdf but sip settings are different (document from 2017) 

[b.winter]

The most consistent and least problem making solution is to have a public IP on the CUBE. The goal is to avoid NAT at all.
The architectural goal should be like in the drawing:

And if a NAT setup is a MUST, then I would configure STUN.

[freddy8827]

Hi b.winter:

   Do you mean we need only upload the root certificate  "T-TeleSec GlobalRoot Class 2" to our ISR CUBE  in security configuration? Any other certificate required? Besides, when I ping "tel.t-online.de" and outbound proxy "55XXXXXXX.primary.companyflex.de", I got no response from them, is this normal? 

Thanks for help !

Freddy

[b.winter]

Hi Freddy,

yes, only the "T-TeleSec GlobalRoot Class 2" certificate is needed.

About the ping: I'm not sure. I don't have it in my mind anymore. But personally, I don't care if the sip-servers or proxies are pingable or not, because you never know. Some for some providers, they are pingable, for others not. And sometimes there is even a differentiation between the providers own internet connection or not. E.g. SIP-Provider provides the SIP-connection and the internet connection --> Ping works. But if you use the same SIP-provider with an internet connection from a different provider, ping is not working anymore.

Long story short: I wouldn't care about the ping.