I'd like to know a simple but effective way to detect an incoming
telephone call (on a POTS) as being initiated from a VoIP telephone.

This could be from a comprehensive up-to-date list (with a reference
to the list) or by using some technical solution (ie. a carrier code
or something similar).

---

Request for Question Clarification by webadept-ga on 07 Apr 2005 12:49 PDT

Hi, 

I'm working on your question here and finding several possible
answers. To narrow down the field and make sure that what I come up
with is going to work for you, could you give me a bit more
information regarding your current setup?

For example, are you using VoIP now, or do you just want to know if
the call coming in originated from a VoIP network?

If you are using VoIP what router and setup do you have (brief
discription is probably all I need with the make and model of the
hardware and service you are using).

thanks, 

webadept-ga

---

Clarification of Question by telephoneguy-ga on 07 Apr 2005 15:09 PDT

We are not using VoIP.  Imagine a call center that takes incoming
calls using a conventional phone system that needs to identify wether
or not an incoming call was made from a VoIP system.

Also of great interest would be the ability to identify wether or not
a specific phone number terminates at a VoIP phone.

ie.  is 313-555-1212 a conventional phone number or a VoIP phone
number on an incoming basis or on demand with just the number to
reference.

Thanks.

---

Request for Question Clarification by webadept-ga on 07 Apr 2005 16:28 PDT

Thanks, that narrows it down quite a bit. I'll get started putting
this together for you with that information in mind.

webadept-ga

---

Request for Question Clarification by webadept-ga on 14 Apr 2005 07:36 PDT

Hi, 

Sorry for the delay here. I'm not finding any "simple" solutions for
this, perhaps  another researcher will have more luck.

webadept-ga

---

Clarification of Question by telephoneguy-ga on 14 Apr 2005 10:37 PDT

Thanks for the questions.  Hopefully someone can help out.

With hardware access this is possible.
There is a forum I found that discusses VOIP. Perhaps someone there can help:
http://forums.whirlpool.net.au/forum-replies.cfm?t=323230&p=-1

I see at the above post they are talking about detecting the VOIP
"Long Silence". I believe this might be relevant.

B Mann Consulting thinks it's not possible to detect VoiP traffic:
http://www.bmannconsulting.com/node/1055

This article suggests, "A protocol analyzer such as RADCom's
AudioPro-PrismLite combination can automatically detect VoIP traffic
streams and even play them back as audio files."
http://www.networkcomputing.com/1001/1001ws12.html

And here is a page on the subject:
http://www.radcom.com/radcom/about/pr110199.htm

You have to register to access the tech pages at Rad Com, but I looked
over some of their docs and they seem to be able to help you out.