Avaya IP Office with Spectrum Charter SIP trunks

[chadphoneguy]

We are doing a cutover from a PRI to SIP trunks from Spectrum Charter on a customer Avaya IP Office system.
Spectrum Charter is not the normal carrier that we usually work with on most of our Avaya IP Office customers, as this is quite a distance away from us in terms of geography. So I went to the support.avaya website and found a job aid for using Spectrum Charter SIP trunks. However, Spectrum Charter insists the LAN static IP has to be within the same range as the LAN2/WAN advice which connects to the SIP device. This doesn't seem to work at all. Can anyone give advice on this that has worked with Spectrum Charter SIP trunks on an Avaya IP Office. Please read the paragraph below from the tech that was onsite.
Also, FYI, we upgraded the IPO to 11.0 and then installed 8 SIP trunk licenses as well.

***Here is a description from the tech that was out there.
"The Avaya job aid for programming Sip trunks on an IPO with Charter Spectrum shows to program it through the WAN port. Our tech support says the WAN IP should have been provided from the carrier and use that as the LAN2/WAN IP. Spectrum says the IP should be within the same range as the IP of the IPO LAN1 port. But this doesn't make sense or work. When Spectrum showed up to test their switch, the tech programmed his laptop with the IP of the WAN (192.168.168.50) and was able to receive calls. Also they were able to ping the IPO (192.168.168.5) and said their programming is complete and are just waiting on us to configure the IPO. I followed step for step of the Avaya job aid and kept getting an error saying the LAN1 and LAN2 cannot be on the same subnet range. I searched videos as well and was wondering if since their switch and our IPO are on the same network if we should be using the LAN1 for the traffic? Any help is much appreciated. Thank you.

 

[derfloh]

I don't see any reason for that comment of Spectrum. IPO doesn't allow to use the same subnet on both interfaces (what makes sense - how would you handle IP routing otherwise?).

You have to see the SIP Trunk side (LAN2 in your case) and the Endpoint side (LAN1 in your case) independently. To bring the SIP trunk up and running only the LAN2 side has to be configured. If the IP of LAN2 is defined by Spectrum AND your LAN1 side uses the same subnet you either have to adjust LAN1 IP settings or you have to ask Sepctrum to use an IP of another IP range.

Need some help with IP Office?

https://www.fwilke.com/home

CLI based cale blocking:

https://blog.fwilke.com/ip-office-block-calls-from-specific-cli/

SCN fallback over PSTN:

https://blog.fwilke.com/ip-office-scn-fallback/

 

[chadphoneguy]

I've passed this message on to the tech and he said this makes sense. He'll head out there and try this.

 

[Michael Brown]

We are running overlapping LAN1/LAN2 IP ranges here for just about 2 years on IPO 10.1 Server Edition and have not had a problem. We did not plan on doing that but due to not being able to run a SBC we had to make some adjustments to our structure at the last minute. We configured everything through the web and it is a lot more forgiving then the manager app so it just took the config (We may have used the "Platform View" for this).

Just as an example below is the general configuration we use.

Example Info
Comcast SBC: 10.20.20.10/24
IPO LAN2 (SIP Trunk): 10.20.20.21/24
IPO LAN1: 10.20.20.20/24

That being said I don't think I would have chosen that setup but it does work.

Sorry I forgot to mention I believe we entered a static route so that all communication to 10.20.20.10/32 will go out LAN2. I believe that is what makes this configuration work.

 

[janni78]

If LAN1/2 are on the same subnet why not just run the SIP trunk on LAN1 ?

I probably only used LAN 2 in 1% of a installs.

"Trying is the first step to failure..." - Homer

 

[Michael Brown]

We were migrating from a hosted Cisco system which we did not control the routing of we we needed to utilize LAN2 and put it on another vlan/subnet to utilize them as a SIP trunk. We initially were going to setup a dedicated network for the SBC but once we saw Comcast provided it own form of SBC it was not needed but we did not want to spend the extra time getting them to update their configs with a new topology so we just merged the two.

I should mention that we are virtual so for us using LAN2 does not take anything. Besides it being kind of nice to see internal traffic compared to external traffic you are right we could have merged the two. At this point I am scared to touch it as it as been working so well.

 

[derfloh]

Perhaps the provider can change the SBC IP if you call them...

Need some help with IP Office?

https://www.fwilke.com/home

CLI based cale blocking:

https://blog.fwilke.com/ip-office-block-calls-from-specific-cli/

SCN fallback over PSTN:

https://blog.fwilke.com/ip-office-scn-fallback/