nanog mailing list archives

Re: SIP trunking providers


From: Owen DeLong <owen () delong com>
Date: Mon, 20 Jul 2015 14:33:41 -0700

The TDM network is rapidly being eliminated. The major telcos have been moving their backbones to VOIP and higher 
levels of oversubscription as a result for years now because of the very large cost savings that can be achieved.

International TDM may still be pretty common, but domestic TDM is rapidly becoming as popular as a Strowger.

Owen

On Jul 20, 2015, at 06:49 , Naslund, Steve <SNaslund () medline com> wrote:

End to end delay is not the most limiting factor.  Jitter is the issue and packet drops are the other issue that 
matters (more importantly the distribution of drops).  I think the best reason to select the local provider over the 
distant one is that the sooner he gets off the IP network the less impairments he will run into.  The TDM network as 
antiquated as it is, is less susceptible to congestion and call impairments than an IP backbone network is.  I can 
tell you from running a bunch of International VOIP networks that they are just not as reliable as TDM.  The average 
internet connection just does not meet the reliability standards that the TDM voice network has achieved.  IP 
networks are affected by congestion and routing issues whereas the TDM network seldom has these type of problems.  An 
outage on a TDM circuit rarely affects other TDM circuits so they see a lot less higher level outages.  I can 
understand why he does not want to haul his voice cross country over IP when he is exiting locally most of the time.

Yes, I understand that the carrier might very well be hauling that traffic via IP even after he gets to his gateway 
point but at that point it becomes their problem to deal with. 

Steven Naslund
Chicago IL


If you’re going to the PSTN, who gives a shit where you do the interconnect as long as its within 100ms.

If most of your calls are VOIP<->VOIP within Chicago, then it makes some sense to set up a box and just send the 
external calls out to the trunking provider where >you no longer really care where they are.

Absent significant network  suckage, there’s no place in the contiguous US that isn’t within 100 ms of any other 
place in the contiguous US these days.

Owen



Current thread: