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Using Cisco CCUM 11.5 and can't connect to my ITSP

James B
James B asked
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Hello I'm using CUCM 11.5 and using SIP phones. I have my DID's and looks like I have what I need to have setup so that I can connect to my ISTP. but when they dial in, they cannot establish a connection to download their config files.

I wanted to know what else do I need to setup in CUCM? For SIP phones?
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Timothy EstesSr. Voice Engineer
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Commented:
A little clarification needed...
If your phones are on the Internet and connecting to an 11.5 Call Manager, they'll need to have an Expressway server to proxy the connection. If the phones are on your network, all they need is a valid DHCP Option 150 with the IP of your Call Manager and IP connectivity to your Call Manager.
Which method are you using in this case?

Author

Commented:
they have Dhcp option 150 from Server 2016 and has the firmware and configs from tftp32 server. In other words server 2016 has the ip address of the tftp server?
Timothy EstesSr. Voice Engineer
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Commented:
Typically the Call Manager is used as the TFTP server natively. Using TFTP32 adds necessary complexity if the phones have IP Connectivity to the Call Manager.

Author

Commented:
ok i'll try that

Author

Commented:
Thanks for the advise! I was able to use the call-manager as a tftp server with option 150. I'm just still trying to figure out how to create a sip connection with my ITSP so that I can dial out to the world.

I was able to call myself with my DX650, 8961 and 8941 phones.
Timothy EstesSr. Voice Engineer
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Commented:
Typically, SIP connections from Call Manager go through a CUBE (Cisco Unified Border Element ) first. CUBE runs on ISRs, usually 4300 series routers if you're going with new stuff. It is "possible" to make a SIP connection to a TSP with Call Manager alone but it is not recommended and usually not supported by the TSP.

Author

Commented:
Good, because my ISR 2921 has CUBE? and also an ISR board with memory for Unity, When I purchased the router it had CME 12.0 on it but I wanted to use CUCM.
Sr. Voice Engineer
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Commented:
The configuration of your CUBE for SIP service with your TSP depends greatly on what your TSP requires. Some require SIP-UA, some require you to tell them the IP you'll be coming from. Also, if your ISR is behind your firewall (highly recommended) you might want to think about SIP-ALG.
You'll configure a SIP trunk between your CUCM and CUBE, then another between the CUBE an the TSP. There is a LOT to do on the CUBE for these trunks.