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Iip office 500v2 SCN through cisco VPN

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phoneguy97

Technical User
Oct 29, 2011
14
US
Hi Everyone,

I have five IP Office 500v2 all running 7.0(232702). I have VPN tunnels established between all sites using Cisco 5505 and 5512 firewalls. We are experiencing dropped calls at random call times Anywhere from 30 secs to over an hour. The problem seems to be worse between 8AM and 10AM. When the calls drop the phones display unobtainable and when the voicemail is not accessible users see busy. We have spoken with Cisco and they have told us after testing and monitoring that the VPN is not going down. We have also setup QoS on the firewalls and we are still having this issue. Below are some syslog files we have collected from one of the phone systems. It looks like the SCN trunks may be going down. Any help is much appreciated. We were also thinking of trying to use the built in ipsec capability on the phone system and bypass our network gear all together. Should we do this?


2013-09-30 17:21:06 User Info 10.1.99.225 Sep 30 17:21:19 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 30 IP Address: 10.1.97.225
2013-09-30 17:20:47 User Info 10.1.99.225 Sep 30 17:21:00 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 30 IP Address: 10.1.97.225
2013-09-30 17:20:28 User Info 10.1.99.225 Sep 30 17:20:41 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 30 IP Address: 10.1.97.225

2013-09-30 13:22:49 User Info 10.1.99.225 Sep 30 13:23:01 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225
2013-09-30 13:22:30 User Info 10.1.99.225 Sep 30 13:22:42 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225
2013-09-30 13:22:11 User Info 10.1.99.225 Sep 30 13:22:23 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225

2013-09-30 13:19:20 User Info 10.1.99.225 Sep 30 13:19:32 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225
2013-09-30 13:19:03 User Info 10.1.99.225 Sep 30 13:19:15 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 30 IP Address: 10.1.97.225
2013-09-30 13:19:01 User Info 10.1.99.225 Sep 30 13:19:13 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225
2013-09-30 13:18:44 User Info 10.1.99.225 Sep 30 13:18:56 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 30 IP Address: 10.1.97.225
2013-09-30 13:18:42 User Info 10.1.99.225 Sep 30 13:18:54 10.1.99.225 TRP|No response to IP trunk call request. H.323 Line: 20 IP Address: 10.1.98.225


 
An unstable VPN tunnel will do this. What is the broadband at each end? 8am to 10am sounds like when everyone who gets into work is whoring the interent before they start work properly! :)

ACSS - SME
General Geek

 
Hi Hairlessmonkey,

We originally though the internet providers at each end was the issue as one was centurylink bonded DSL 20/2 and the other end had charter cable 30/5. We put in a DSL connection at the location with Charter and dropped ping times from avg 130ms to 150ms to around 70ms over the VPN tunnel. The new tunnel is running between a Cisco ASA5505 and a Cisco 1921 router. Both ends have QoS but we are still seeing the problems. Cisco is saying that they are not seeing any problems with the VPN after setting up syslog server at both locations and then sending logs to Cisco for review. I've also sent them packet captures and they couldn't see what was causing the problem.

I've been thinking of setting up policing to limit all other traffic to a small amount of bandwidth to see if this corrects the issue. I agree that seeing issues early in the morning is concerning and makes me think bandwidth is part of the problem. Could it be the Cisco inspection engine messing with the packets? Any thoughts on the phone system VPN? Ive seen mixed reviews on it but am thinking this would eliminate the Cisco VPN as a possible issue or would this make thinks worse?
 
You have a problem with one or both Connections.
I doubt that the routers are the problem.

BAZINGA!

I'm not insane, my mother had me tested!

 
The problem is happening with all of our sites to some degree. I'm posting mainly about the site having the worst problems. From the syslog files te trunks are unreachable. The VPN connections are still up but for some reason the SCN trunks seem to be losing connection to each other. Primarily we cannot call the site internally that is having the worst time with this problem. Other sites its mainly effecting access to voicemails. They get a busy on the phone display when trying to listen to vm's. To answer the last question systems on both sides show trunk being down.

What is the opinion on using the built in VPN. I'm thinking our VPN encryption may be effecting the packets in some way and not allowing everything through. Any ideas on this idea?
 
Are you sure that there is enough bandwidth?
It sounds like that there is no voice vlan configured with QOS.
When there is too much data used then it will probably disconnect the SCN.
I think this is because it happens on certain times.


BAZINGA!

I'm not insane, my mother had me tested!

 
tlpeter said:
Are you sure that there is enough bandwidth?
It sounds like that there is no voice vlan configured with QOS.
When there is too much data used then it will probably disconnect the SCN.
I think this is because it happens on certain times.

I would have to agree with @tlpeter have you created a VLAN for voice?
 
I have policing setup for all other traffic other than VoIP related. All other traffic is limited to 8Mb down and 256Kb up. I've tested this and it works. What would setting a vlan for phone system help with policing in place? We don't have any VoIP phones. They are all digital sets connected directly to the system.

Don't confuse my question as not agreeing I'm just asking because I don't know and I wanted to give a little more information.
 
The SCN traffic is VoIP.
And that should have priority.

BAZINGA!

I'm not insane, my mother had me tested!

 
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