PBX Issue

[dcanady55]

Hello,

To be up front we don't use Cisco VOIP it's MITEL.

I have two sites that cannot talk to each other. At first I thought it was a  call routing issue so I checked all the routes and made sure each PBX has the  correct numbers and IP addresses all is fine nothing has changed. Then when I tried pinging each  others IP address from within the Mitel I couldn't reach each other. I started down the  network path but from each router I can ping the others PBX IP address so I know  the route is there.

The PBX know's its default gateway and can get there just fine and can ping all the other PBX's IP's just fine. Am I missing something obvious.

Thanks,

[Jon Marshall]

How is the connection from each site made ie. is it just a WAN, VPN etc.

Do you have any acls in place.

What does a traceroute show (i appreciate you may not be able to do a traceroute from the PBX).

I have no experience with PBXs so if it is an issue with that you may need to move the post to the VoIP forums but we can look at the routing first.

If the PBXs don't support traceroute can you try an extended ping from the L3 device connected to one PBX using the source IP as the IP that is on the same subnet as the PBX.

Jon

[dcanady55]

Hi Jon,

Thanks for the reply. It's a Point to Point T1. There is no ACL and I have never looked into doing a trace route from the PBX it turns out I can. Now I haven't used this alot but when I did the trace to the IP address of the other PBX it gives me the first 4 hops then request time out all the way till 30. I will look at at the last hop and see what I can figure out.

Thanks,

[dcanady55]

Little confused now. I assumed when I went to the last hop on I wouldn't be able to ping the IP address of the PBX I'm trying to communicate with. I was able to ping it....not sure what I'm missing or what steps I would take next.

Thanks,

[Jon Marshall]

Have you tried pinging both ways ie from one PBX to the other and then the other way round ?

Also do this with the traceroute and see how far they get in terms of hops from both sides

Jon

[dcanady55]

Yes, neither PBX can ping each other. I think I have it figured out or narrowed down.

PBX A Router A

PBX B Router B

Router A can ping PBX B and Router B both data and voice vlan, Router B cannot ping PBX A voice vlan but can ping the data vlan's IP.  When I look through the routing table of Router B there is no route to Router A's voice vlan and Routers A gateway of last resort cannot get there either. We just changed from OSPF to EIGRP. I don't have extensive experience tshooting OSPF and very little with EIGRP. I'm studying for the CCENT currently.

Thanks,

[dcanady55]

Jon,

could you answer this. When I do a trace route from PBX A to router B's mgt IP it stops after 3 hops. Like I said in the post above when I go to that last hop I can ping that IP and PBX B from that router so if the trace route stops at that hop what is that telling me in this scenario?

Thanks,

[Jon Marshall]

So it sounds like the issue is that router B does not have a route for the voice vlan at router A ?

So which device is responsible for routing that voice vlan ie. what is the default gateway of the voice vlan is it router A ?

Whichever device it is can you log onto it and check the EIGRP config. If you want you can -

1) tell me which vlan is the voice vlan

and

2) post the EIGRP config from that device

Jon

[acampbell]

Hi,

Most issues like this are caused by the ip routing or codec isues.

Can the PBXs ping each other.

If you are using Ip phones can the phoness at site A ping the phones at site B

Do you have any firewalls in the ip path, if so have you enabled the correct udp port for the voice RTP streams.

For codec issues is one end trying to use g711 and the other g729 for example, if this is the case you need transcoding resources

Regards,
Alex.
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