T-1 over Ethernet (WAN)

Unanswered Question
Apr 27th, 2010

Hello and thanks in advance for any advice and help you can provide me ... I can't seem to get a straight answer on this project and I'm really hoping to get some help with it here.

I'm working on a project to replace point-to-point T-1's with an ethernet WAN that utilizes 40-100Mbps links between sites.  Data is flowing over the new WAN without a problem, but we can't remove the old T-1's because our tired old phone system still requires T-1's for office to office calling.  What I'd like to do is configure my routers to 'emulate' a T-1 for these sites so that we can retire the T-1 circuits, but essentially provide T-1 handoffs to our phone system.

The T-1's are currently connected using Adtran CSU/DSU units that split voice and data channels (most sites have 14 voice and 10 data - remember our data uses the new ethernet WAN so the 10 data channels are just a backup if the new WAN has an issue).  I was told by several people that this can't be done, yet some other people have told me it's no problem at all ... I'm hoping it can be done (and hopefully using the equipment I already have - see below):

Our main site has a 3845 and the other sites have 2821 routers.  For testing purposes I have (2) VWIC2-2MFT-T1/E1 cards and (2) PVDM2-16 modules.  I feel like I have the pieces, but I just don't know how to configure them to do what I need.

Thanks again

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Edison Ortiz Tue, 04/27/2010 - 10:25

You will have to modify your PBX/Call Manager setup to support Voice over IP.

We do have a forum dedicated just for that technology so please direct your question there.



cgyomber Wed, 04/28/2010 - 05:30

Thank you for responding ... I understand what you're saying but technically I'm not looking to implement some kind of VoIP solution.  I basically just need to get emulate a T-1 circuit over ethernet so that I have a T-1 handoff at each site that currently has a point to point T-1.  Take the equipment that's going to connect to the T-1 out of it for now ... I still would need to get a T-1 setup over ethernet which is my core issue.

I see that Cisco has 2 network modules that do this, but I was hoping to be able to make this work with equipment I already have ... the  (2) VWIC2-2MFT-T1/E1 cards and (2) PVDM2-16 modules.

If you still think this is better suited in one of the VoIP forums, let me know and I'll move it over there.

Thanks again for your help

Edison Ortiz Wed, 04/28/2010 - 07:08

I'm afraid your requirement is not technically possible. You can't terminate your remote locations which are using T1 to your Ethernet connection at Headquarters..

cgyomber Wed, 04/28/2010 - 07:20

I'm either not explaining this properly or you're not understanding what I'm trying to do ... they aren't terminating T-1 at one end and ethernet at the other ... it would be T-1 at both ends with ethernet in between.  Here's what I was thinking:

PBX T-1 Card ---> Port on VWIC2-2MFT-T1/E1 in Cisco 3845 ---> GE0/0 in Cisco 3845 ---> Ethernet Handoff (WAN) ---> WAN ---> Ethernet Handoff (WAN) ---> GE0/0 in Cisco 2821 ---> Port on VWIC2-2MFT-T1/E1 in Cisco 2821 ---> PBX T-1 Card

(The GE0/1 ports on the routers connect to the LAN at each site)

Because we have point to point T-1's from our main site to each of our locations, I'd end up with a few VWIC2-2MFT-T1/E1 in the 3845 and most likely a single VWIC2-1MFT-T1/E1 in the 2821 routers at the branches.

I'm sorry if I keep pushing it, but it seems to me that this can be done using this equipment

Thank you

Paolo Bevilacqua Wed, 04/28/2010 - 07:28

That is called Circuit Emulation and Cisco sells modules that do it.

Now please explain why you think you can't use VoIP ?

cgyomber Wed, 04/28/2010 - 07:35

yeah, I know about those modules but my understanding is that they're EOL now and I wanted to try and stick to using the VWIC2's that I already have.  I figured that I couldn't use VoIP because our phone system is old enough that it 'just doesn't support it' (so says our phone consultants - I think they just didn't want to think about it for more than 30 seconds).  If the solution is to use VoIP and I can make it work with those VWIC2's I'm all for it ... I just don't know how to configure the darn things to do what I need and I couldn't seem to find any config example that was close enough to what I envisioned I had to do to get started.

I'm just now finding a thread that you commented on that sounds darn close to what I need to do (https://supportforums.cisco.com/message/1064012) ... I'm still reading though what you had in there, but do you have any example config that'll do what I'm trying to do that'll at least get me started?

Thank you for responding, I appreciate it

Paolo Bevilacqua Wed, 04/28/2010 - 09:10

Of course VoIP will work.

You must find a reputable consultant or certfied cisco partner to assist in configuration, testin, and troubleshooting.

You cannot do this youself, even if you find configuration examples, at the first issue you would be stuck, because this stuff requires specific experience.


This Discussion

Related Content