IP phone how to communication with other site without voice gateway

[tianwen.zhao]

Hi guys,

    I am a totally beginner of Voice. Our company have Headquarter、Site1 and Site2 

    Headquarter have call manager(CUCM) , site1 have voice gateway(C2900), and the IP Phone function of them is normally

   Now the question is that Site2  is a new site, and it doesn't have voice gateway(C2900). Site2 establish ipsec-vpn between  Headquarter and site1 , so site2 how to use the  IP Phone ?

Thanks

[Jaime Valencia · Accepted solution]

As long as the phones can communicate with CUCM, they can be registered. RTP is between endpoints, make sure proper routing is in place.

[tianwen.zhao]

Thank you for your reply.

So , What 's the purpose of Site1's voice gateway(C2900)?

[Jaime Valencia]

Most likely a PSTN GW or used for FXS, look at the HW specs and configuration to find out.

[tianwen.zhao]

Thank you for your reply.
But I really don't understand what does FXS or HW specs mean......
Is there any relevant information to see ?

thanks

[Shalid Kurunnan Chalil]

Hi, the Voice gateway at site 1 mostly being used for PSTN connectivity.
could you please check if there are any E1/T1 lines terminating at the site 1?

for site 2, as Jaime said, as long as there is connectivity with call manager and routing to the VGW's then you don't see any problem to phone registration and voice packet flows.

Really, you should start your reading on Cisco voice solutions. lots of documentation available on the public internet.

refer the SRND of Cisco call manager

you have to look at your call manager gateway configuration, dial plan and voice gateway itself to understand how the call routing works.

Please let us know if you have any specific queries or faults where we all can help you in a better way..

Regards,
shalid

[tianwen.zhao]

Thank you so much shalid, I think I have a lot of things to learn