IP Trunk through VPN (overlap subents)

[ACECCVP]

Hi Guys,

i Have strange issue here, i would be so happy to hear your input. the issue that we have 2 sites, each site with Avaya S8300. both sites having the same subnet range so we have gone for solution with overlap hiding subnets.

i can ping each site from the other site, i can telnet the remote S8300 and Vis vera, created trunk group, it shows inservice both sides, but when ever you call , get error, and the trace on the remote trunk group is blank, i also tried to register a phone on the remote S8300 but didnt work, it keeps showing discover.


i know voice have an issue with NAT, but all other applications, telnet ,http, many other applicatiosn works fine, except voice.. so any work around for this?

 

[Mitch672]

Yes, you need "dark fiber" and Layer 3 switches to duplicate a VLAN PROPERLY (VLAN trunking) at 2 physical locaitons. Anything short of that, and you are going to have issues, as you have discovered.

There is no other solution, I would suggest different subnets for voice at each location, why do you need the same subnet at each location?


Mitch

AVAYA Certified Expert

 

[ACECCVP]

Thanks for the reply. well, the 2 sites \locations in 2 different cities, 2 seperated companies and now they will merge into one, so they want to connect thier Avaya systems toghers through UP trunking, now when i started to program the Link i found that both sites having the same subnet and they have connected the 2 sites through VPN and they are using the NAT VPN to solve the overlap subnet.


i told him NAT will not with voice... he saids why u can ping and access both systems , why voip is not working with NAT? he wants from to provide him with proof from Avaya.

for Example to configure trunk n Avaya:


local node: processor

far node: S8300 NATED address. not the real address on the remote S8300

 

[Mitch672]

I doubt AVAYA has an "document" you can send him, but using double NATing will never work properly. Change the subnet at one of the locations, and you will be fine, anything else and it just won't work. no one is going to "prove" this to you, it has been tested enough time to know...


Mitch

AVAYA Certified Expert

 

[ACECCVP]

I know thanks mitch. actually im stuck .. none of it manager at the sites wants to change his IP scheme.. its headache for them..