TDMoE or not?


I’ve got a client that is looking to connect their phone system over the brand new 100Mbps WAN they now have. The phone system is currently connected via T1s from the main office to the 9 branch offices. I can easily do this using a RAD IPMux but I’m wondering if I can make it work with Asterisk. Why, you ask? Because they’re not really happy with the system and if I can position this solution to replace their existing setup they will probably do so in the future.

Would it be possible to use TDMoE for something like this? I’m pulling this out of my butt so tell me if I’m on crack:

Each branch office would have a server with a TE110P card that connects to the existing phone switch. That server would communicate back to the main office via a dedicated vlan and connect to the main server that would have a couple TE410P cards that would connect into the main phone switch.

If I remember correctly, this client is only using about 12 channels on each T1. If I can’t use TDMoE I could probably just program Asterisk to pass the calls between systems using IAX or SIP.

Thanks for your help!


Use IAX2, not TDMoE. TDMoE is most useful when you have a dedicated ethernet span (one machine to another). As I recall it is mac-based and does not route (making it probably unsuitable for your system).

IAX2 will route quite nicely. IMHO this is what you should be using. Set up * boxes with PRI cards in each branch office, and one * box at the central point. I recommend set up the PRI cards with the same settings as the existing T1 lines so you can swap back and forth if needed without reconfiguring the site PBX.
Do the same thing for the main PBX, although I have a feeling you can get some economy by fully saturating a few PRIs instead of having a handful of half-used ones…

Hope that helps!

helix, question as to why he would want PRI’s in each branch office, instead of just using IAX to trunk to the main office and go over the PRI’s there…the remote office servers wouldn’t necessarily need anything other than an ethernet port, i would think.

i’m probably missing something here, been a long week, so go easy on me :blush:

whoiswes: I need TE110Ps in each branch because of the existing phone system. Sooner or later I’d like to replace this phone system with Asterisk but for the time being I need to tie the systems together like they are now, minus the existing T1s.


gotcha…my bad for not reading more carefully…