routing cs1000 elan

[chrisv]

Until recently the ELAN for our Avaya CS1000 has been strictly layer 2 on the local network.
We have now placed an SMG at a remote location going across a multilink ppp connection. I changed the
ELAN so that it is Layer 3 capable. The boxes can see each other fine so routing is working ok. But the remote SMG can not attach to the CS1000's database so that it can go online. So in summary it works ok layer 2 but not layer 3. Has anyone encountered this problem ? Is there a mtu size limit possibly going on here? Avaya is pointing to a routing issue.

[Michael McNamara]

Hi Chrisv and welcome to the forums!

Are you using a Survivable Media Gateway (SMG) or a Survivable Remote Gateway (SRG)?

As you know there are multiple connections on the CS1000. There is a TLAN and ELAN. It's the TLAN that is usually routeable and accessible for IP phones and for VGMCs (Voice Gateway Media Cards). The ELAN is usually reserved for just the CPU and perhaps a CallPilot or Contact Center (Symposium) communications.

When you created the default route on the CS1000 what gateway did you use? from which interface?

Assuming you have Signaling Servers you can connect to those and use the 'ping' command to test communications to your remote equipment.

Cheers!

[Flintstone]

Hi chrisv,

As Michael mentioned you have two LAN interfaces (ELAN & TLAN) and by default your default gateway usually is setup to use  the TLAN interface. 

We have had lots of issues using SNMP to manage our media gateways.  Sometimes it is the TLAN interface and other times the ELAN interface.  We checked the default gateway settings and it made no sense.  It looked like the Media gateway would use either interface?

CheerZ

[chrisv]

Thank you for the response. We are trying to connect an SMG. (Survivable Media Gateway) Unlike the SRG the SMG apparently requires access to the ELAN for the redudant components to function. It hasn't been a problem until I had to traverse a routable connection. The gateway info is correct and they do see each other but they can not get the necessary info to pass. The packet capture doesn't show any large packets.
Have you ever seen this problem before. Also, there is no firewall involved.

Thanks

[chrisv]

update to SMG issue. After forcing a conference call between the installer and some Avaya engineers it turns out this is not the proper method for getting an SMG to register to the CS1000. As I had suspected the elan should not be routed. Apparently this defeats the purpose of the SMG in the first place. The proper method appears to be using NRS that is a part of the CS1000. I am told that the elan is sensitive to MTU size as well as  packet fragmentation. Hence that is why they don't want you to route the elan. I love it when a plan comes together.

[Michael McNamara]

Very nice... you know you're in for trouble when you (the customer) know more than the reseller (installer).

Thanks for the follow-up!