Subject: RE: [IPTEL] GW knowing the cost of calls

From: "Anderson, Darby" <[email-masked]>
Date: Fri, 19 Oct 2001 11:59:15 -0700

When you say that a G/W doesnt need to know "a" cost of a call, you mean the
G/W on the TERMINATION leg of the call, correct?

-----Original Message-----
From: Cullen Jennings [mailto:[email-masked]]
Sent: Friday, October 19, 2001 12:39 PM
To: [email-masked]
Subject: [IPTEL] GW knowing the cost of calls

The GW should not need to know the cost of any given route in Columbia
Laundry Tokens or any other currency. It changes too quickly and the GW are
a very difficult place to update it. Let's avoid this path.

Cullen

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From: "Cullen Jennings" <[email-masked]>
Date: Fri, 19 Oct 2001 14:04:20 -0700

Ah yes, I should have been more careful on what I said.

I think having a terminating gateway export via some protocol a route like
"I can reach all numbers of the form +1408* and it costs my 0.04 US dollars
per minute plus a setup charge" is a bad idea. Clearly least cost routing is
a hugely important part of what we are trying to accomplish in VoIP but
having the GW need to know the cost of the route is the wrong way to do it.
Providing information that can be correlated with a billing rating engine
like "I can reach numbers of the form +1408* using a trunk connected to
Sprint in the +1 408 263 exchange" seems like a more practical way to
implement least cost routing. Something in the core of the network that is
capable of least cost routing decisions is an easier place to update this
constantly changing price information than the edge GW. Keep in mind people
will often buy a block of minutes from some carrier and once they have used
up those minutes the rate will change dramatically. So you have to keep
track of the number of minutes used by all your GW, not just one, to that
carrier to accurately know what the next call to a given trunk might cost.

If we are talking about an initiating GW instead of a terminating GW, the
carrier it came from and ANI may be important for routing decisions but I
don't see if having much to do with TRIP.

Cullen

-----Original Message-----
From: Cullen Jennings [mailto:[email-masked]]
Sent: Friday, October 19, 2001 12:39 PM
To: [email-masked]
Subject: [IPTEL] GW knowing the cost of calls

Cullen

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From: "Shan Lu" <[email-masked]>
Date: Fri, 19 Oct 2001 18:09:20 -0400

> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Cullen Jennings
> Sent: Friday, October 19, 2001 5:04 PM
> per minute plus a setup charge" is a bad idea. Clearly least 

<Snip>

Just want to clarify that having a GW export all the numbers it can
terminate is actually a very useful feature. For example, a gateway may
have media trunks to certain end exchanges that are identified by
NPA-NXX. Then the gateway will need to export this information out, like
"I can terminate all calls starting with +1-301-222". 

Shan Lu