SCN dialing only works one-way intermittently

[tmckeown]

Hi,
I've got two phone systems, a IP412 and an IP406. They are in different states and are programmed for SCN so we can dial extensions from either location and get to anyone within the domain. In the last few weeks, I'm finding that users on the IP406 system are (intermittently) unable to initiate calls to the IP412 system. Everyone on the IP412 can make direct calls via extension number to the IP406 system. Can someone give me a few ideas on what to look for and how to diagnose the problem? It seems that this problem began when we changed the ISP for the IP412 system. We went from a local carrier to Frontier and now have a 100MB up/down connection. So, speed doesn't seem to be the cause. Could it have anything to do with VCM usage? It's very odd. yesterday it worked fine all day and today they can't call extensions from the IP406 system. it has been working fine for 8 years. It seems to have only started having the problem when we changed ISP. I had them check MTU and all seems fine there. Got any ideas?

IP412 3.2 (69)
IP406 3.2 (69)

Thanks for the help

 

[IPGuru]

It seems that this problem began when we changed the ISP for the IP412 system

This is whre the problem will be.

Are you connecting through a VPN or do your IPO's have public IP Addresses (if this is the case then you need to change it urgently)

you may have a fast service but otherthings also affect VoIP & SCN.

Latency
Jitter
Traffic management.

What sort of ping times do you get between sites? Are you remote sites withthe same ISP? if not then hops between ISP may not support QOS.
is your new ISP blocking or restricting traffic? (this should not be a problem if using a VPN



A Maintenance contract is essential, not a Luxury.
Do things on the cheap & it will cost you dear

 

[tmckeown]

Thanks for the reply. Let me answer some questions...
We have a IPSec tunnel between the two sites. Nothing is filtered via the firewalls
I can ping the remote IP Office 406 with a time of 77-80ms
the remote site can ping the IP 412 with a time of 80-86ms

Its really kind of odd and I haven't been able to figure out why calling from the remote site becomes intermittent. Yesterday they emailed to say they couldn't dial anyone's extension at the main office. I dialed their extensions and got through right away. A couple hours later, they could call to the main office. Then right as I was leaving, I got another email saying they couldn't dial extensions again. Very odd and very hard to trace down the source of the trouble.
I do have Sonicwall firewalls and I saw their was some trouble with them on version 5 of IP Office. But, since we are on 3.2, I didn't figure that would be an issue.
Any help would be great and much appreciated.

 

[IPGuru]

IPsec VPN is good
Ping times are good

Is your VPN a "Nailed up" connection or is it established "On Demand" ?

you will need to be tracing this issue on the network at the time it actualy ocours but everyone here will be supprised if it does not prove to be a network issue.


A Maintenance contract is essential, not a Luxury.
Do things on the cheap & it will cost you dear

 

[tmckeown]

Sorry for the late reply. I thought my response posted weeks ago but now I see it didn't. Our VPN tunnels are permanent. I too won't be surprised if it is a problem with the network, but I've been completely unable to trace down the source of the problem. Its very intermittent. I have our ISP looking into also. They say everything is fine on their end, but all the complaints I get from VPN users suggest otherwise. I'm thinking there is a lot of packet loss happening but I'm unsure how to track down such an intermittent problem.

 

[tmckeown]

Anyone have any ideas? I'm still pulling my hair out trying to figure what's wrong.
two offices: Chicago and LA
Chicago can dial extensions in LA and be connected instantly.
LA tries to dial and extension in Chicago but gets one of a couple errors:
they try to dial 370 (which is my extension in Chicago)

1) they dial 3 and get a short touch tone, they dial 7 and it seems to hang it up
2) they dial 3 and then they dial 7 and get a quick beeping and the phone display says "Incompatible"

The tunnel between the offices is always up and I'm actually logged into servers at both sites to monitor the situation. So, I'm thinking the SCN is up and running. Why would dialing extensions work only one way though?
Any help would be greatly appreciated.

 

[amriddle01]

This will no help other than to narrow your focus onto your Sonicwalls.
I had this exact issue a while back but with sites linked over a Cisco to Cisco VPN. Every now and then a site couldn't call the other sometimes they could, sometimes every other call would work etc etc. Long story short, after getting sick of the finger pointing I ended up putting the systems local to each other to prove SCN works by itself, then separated them again over non Cisco VPN and it worked, back on the Cisco to Cisco VPN issue was back.

I left it in the hands of the IT dude,[pre][/pre] but stopped dealing with them before he found a fix...

SCN is very limited in its settings, not much to get wrong. This will be the Sonicwalls or the underlying link, I can pretty much guarantee that

 

[tmckeown]

Thanks for the reply. It's very odd. It all worked just fine till we change ISP. I've had numerous cases for the same thing open with Frontier (ISP) for two months. They say they aren't filtering anything and that the problem is our Sonicwall firewalls. I would believe that IF the problem had been there earlier. I've been tearing my hair out trying to figure out what's wrong. The systems are so far away from each other that getting them in the same building is going to be impossible.
Is there a way to monitor the SCN? I know that must be a real dumb question but I don't see anywhere to monitor the status of the SCN. Maybe its hidden somewhere in the monitor program?

Thanks for any help you can give.

 

[amriddle01]

Some carriers still see protocols even within VPNs and can effect/drop the traffic even though youw would assume they can't. It was mentioned here a while back that one carrier specifically was stopping VPN phones working.

Watching SCN in monitor will be of limited use as as you would see is suddenly the traffic stop coming in/going out and the route shown as OOS, wiresharking both sides would be better and at a specific time you know it happened comparing to see what packets/protocols didn't make it

 

[tmckeown]

I will give that a shot. Thank you.

 

[mforrence]

1) they dial 3 and get a short touch tone, they dial 7 and it seems to hang it up
2) they dial 3 and then they dial 7 and get a quick beeping and the phone display says "Incompatible"

If this is true, then it isn't the network, but a shortcode or something in that IPO. The network only comes into play once the extension has been dialed

 

[amriddle01]

I must admit I didn't read all the info in all posts, I missed those dialling references, but an SCN dropping can give funny results to a shortcode that works when it's up. However posting the "dial" shortcodes you use can't hurt

 

[amriddle01]

An extn that works sorry....it ends up matching codes where it would normally match an extn

 

[tmckeown]

I thought that SCN traffic does NOT need a short code to direct the call across the tunnel. Am I missing something? Its always worked before we changed ISP. Neither side has any short codes that apply to extensions at the other location.
I was thinking of trying to temporarily reconnect our old ISP to an extra firewall I have around here and setup the tunnel as it used to be. That would tell me if it is an ISP issue.

 

[amriddle01]

No it doesn't, but when it goes down each IP Office basically completely forgets about the other extns in the SCN and starts trying to match the numbers dialled to your system shortcodes, that results in the odd tones/responses you get when it goes down

 

[Bas1234]

Networking License still there and valid on both systems?
Disabled H.323 Transformation on the Sonics?

___________________________________________
It works! Now if only I could remember what I did...

Dain Bramaged (Avaya Search tool

http://tinyurl.com/bas1234

)
______________________________________

 

[tmckeown]

Do All the licenses on both systems do show "Valid", though I'm not sure which one pertains to networking.

I show in the mail location:
Additional Voicemail Pro (ports)
eBLF
Integrated Messaging
Phone Manager Pro (per seat)
Phone Manager Pro IP Audio Enabled (users)
SoftConsole (users)
SoftConsole (users)
SoftConsole (users)
SoftConsole (users)
SoftConsole (users)
SoftConsole (users)
Voicemail Pro (4 Ports)

In LA:
SoftConsole
Voicemail Pro (4 ports)

I do not have H.323 Transformations turned off. I find that with it turned off, The other two locations that have an IP Phone connected via the tunnel take 10-20 minutes to register and start functioning. With H.323 turned on, they connect withing a couple minutes. I did try a test yesterday and turned it OFF on both LA and our main sonicwall. They still couldn't dial our extensions from LA. We could still dial theirs.

Pretty odd mess eh? I'd love to resolve this. It's been kicking my butt for two months.

 

[Bas1234]

Try to delete both SCN trunks and built them from scratch. Default you only need to enter the IP from the other side and give it an unique incomming and out going group ID.

SiteA inc 1020 outg 1121
SiteB inc 2010 outg 2111

___________________________________________
It works! Now if only I could remember what I did...

Dain Bramaged (Avaya Search tool

http://tinyurl.com/bas1234

)
______________________________________

 

[tmckeown]

Here's what I have in Routes: LA subnet is 10.10.10.0 Chicago is 10.11.0.0

LA Routes:
IP Address Mask Gateway Destination Metric
10.10.10.0 255.255.255.0 10.10.10.1 LAN1 0
10.11.1.0 255.255.0.0 10.10.10.1 LAN1 0

Chicago Routes:
IP Address Mask Gateway Destination Metric
10.11.1.0 255.255.0.0 10.11.1.1 LAN1 0
10.10.10.0 255.255.255.0 10.11.1.1 LAN1 0
192.168.111.0 255.255.255.0 10.11.1.1 LAN1 0 (home office 1)
192.168.112.0 255.255.255.0 10.11.1.1 LAN1 0 (home office 2)

Lines in LA:
11 IP
gateway: 10.11.1.11 (ip office in chicago)
comp: G.729(a)
H450 Support: H450
Checked: Enable faststart, Allow Direct Media Path, Voice Networking, Fax Transport Support

Lines in Chicago:
10 IP
gateway: 10.10.10.11 (ip office in LA)
comp: G.729(a)
H450 Support: H450
Checked: Enable faststart, Allow Direct Media Path, Voice Networking, Fax Transport Support

Am I missing something? It worked for 8 years without problem. After the ISP change in Chicago, it became intermittent.

 

[amriddle01]

That's looks fine, you don't however need the routes for local traffic (i.e. 10.10.10.0 255.255.255.0 10.10.10.1 LAN1 0 for LA), they aren't required or used...as it's local