02-10-2009 08:35 AM - edited 03-15-2019 04:07 PM
I am calling an external number through a CIPC softphone that is connected to CME. The CME has a dial-peer that goes to an AS5300 gateway. The gateway makes the call out of the PSTN and rings the phone. When I pick up the phone there is dead air. Where should I start to troubleshoot? TIA.
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02-10-2009 08:37 AM
Do you have a firewall between CIPC and CME, or between routers ?
02-10-2009 12:14 PM
A number of things:
1) Firewall
2) ACL
3) Routing problems
4) Odds and Ends of routing commands - ip verify unicast reverse source, no ip classless, no ip routing
5) Bad DSP
6) Bad b-channel
7) Errors in the RTP protocol
8) NAT errors
9) VPN ACLs
10) Gateway bugs
-nick
02-10-2009 08:37 AM
Do you have a firewall between CIPC and CME, or between routers ?
02-10-2009 08:51 AM
Thanks for your reply. Yes, I have access-lists. I didn't even think of that for some reason. Which ports are necessary for sound to travel properly?
02-10-2009 08:55 AM
02-10-2009 10:39 AM
I am suspecting a routing issue. I need a little more information. When I establish a call from my CIPC is the RTP stream going to the gateway directly or is it going to the CME which is redirecting it to the gateway?
02-10-2009 10:42 AM
If your CME is using a VOIP protocol to reach another gateway (H323/SIP), then your media will be terminated on CME.
You can check this on your computer fairly easily by installing wireshark.
For hard phones you can go to the website of the phone and it will tell you, but CIPC is on your PC so it's different.
-nick
02-10-2009 11:00 AM
Also CIPC has web server that gives you information.
02-10-2009 11:05 AM
Do you happen to know which port it listens on? I only show two ports open with TCPView. 56583 which is connected to CME at port 2000 and 58932 UDP which definitely isn't a webserver.
02-10-2009 11:07 AM
RTP ports are negotiated dynamically.
Browse to phone address or press ? twice rapidly to get informations about RTP.
02-10-2009 11:13 AM
I am talking about the web server that CIPC has. How do I access that?
02-10-2009 11:34 AM
I have verified connection between CME and the gateway connected to the PSTN. I setup an access-list on the CME interface:
permit ip host ip.add.of.gw host ip.add.of.cme
and I put an access-list on the gateway:
permit ip host ip.add.of.cme host ip.add.of.gw
The counters go up on both of them. Also, I can ping between the two without issue. Is there something beyond firewall issues that would cause no sound?
02-10-2009 12:14 PM
A number of things:
1) Firewall
2) ACL
3) Routing problems
4) Odds and Ends of routing commands - ip verify unicast reverse source, no ip classless, no ip routing
5) Bad DSP
6) Bad b-channel
7) Errors in the RTP protocol
8) NAT errors
9) VPN ACLs
10) Gateway bugs
-nick
02-10-2009 01:51 PM
Alright... it was definitely a combination of firewalls and ACLs. Thanks for your help fellas.
02-10-2009 01:53 PM
You are welcome. Thanks for the nice rating and good luck!
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