We are currently running a TCL script on a 3745. The CPU maxes out at about 500 concurrent calls.
We have purchased a 7206VRX with NPE-G1, hoping this would be able to support a much greater number of calls. Running exactly the same TCL script, the 7206 CPU maxes out at around 800 calls.
We were expecting a much greater number of calls from this 7206. It's a bit hard to get stats fo this kind of thing but the PPS figures for NPE-G1 is about 4x that of the 3745, so I was expecting it to handle roughly 4x the number of calls.
1) Does the TCL script always use the router's main CPU? Is there a way to make it use the NPE-G1's additional processing power?
2) "show processor cpu history" just seems to show usage of one CPU, is there any way to see what load is on the NPE-G1's CPU?
3) Any other reasons why we are not getting the expected results?
 

Our TCL does not play any media files, it is carrier routing only. It is not doing any transcoding either. The memory is absolutely fine, there is 1GB of RAM and it never goes above 20% usage. The problem is CPU, not memory.
 

OK thanks for that Leon but it doesn't really answer my question.
 
I am not asking why I can only get 500 calls on the 3745, I already know this. The TCL is quite complex and the call traffic is low ASR and short duration, meaning high CPS. So 500 concurrent calls on the 3745 is quite normal and expected.
 
What I want to know is why the 7206, which is theoretically 4x as fast, can only do 50% more calls than the 3745 instead of 300% more? Is it only using the router's built-in CPU instead of the NPE-G1's CPU? How can I determine this, or change it?
 

Thanks for trying to help Leon, but you're really not telling me anything useful. If I could reduce the TCL complexity, I would have already. What I want to know is why the 7206 is not as powerful in practice as it is on paper. Do you (or anyone else) have an answer to this question?
 

the interface cards on a 720x are a lot more powerful than those of the 37xx. Where as the 37xx can handle a few hundred thousand PPS the 720x can do well over a million PPS. On the other hand, the CPU, memory and bus architecture of the mother board may not be that much faster.

The unfortunate reality is that boxes are routers designed from the ground up to move data packets. in a voice world your mileage may vary.

PS I moved to 3845s with newer IOS and there was no increase in max CPS whatsoever but I can prove that the 3845 moves data packets faster and handles SIP a lot better.

I’ve been using TCL for voice on IOS a lot longer than most of the techs around here and unless you work for a large corporation like AT&T or so, don’t expect any feature requests or bug fixes in a hurry.

Leon



From: Cisco Developer Community Forums
Sent: Thursday, November 15, 2012 11:12 AM
To: cdicuser@developer.cisco.com
Subject: New Message from Mark Alliban in Voice Gateway API (VGAPI) - TCL-API: RE: TCL CPU usage

Mark Alliban has created a new message in the forum "TCL-API": -------------------------------------------------------------- Thanks for trying to help Leon, but you're really not telling me anything useful. If I could reduce the TCL complexity, I would have already. What I want to know is why the 7206 is not as powerful in practice as it is on paper. Do you (or anyone else) have an answer to this question?

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If money is no object then talk to the cisco product manager about the ASR series of routers. If you want real world options then buy Ten 3745s. they are about $200 each on ebay.

Leon

From: Cisco Developer Community Forums
Sent: Friday, November 16, 2012 4:49 AM
To: cdicuser@developer.cisco.com
Subject: New Message from Mark Alliban in Voice Gateway API (VGAPI) - TCL-API: RE: TCL CPU usage

Mark Alliban has created a new message in the forum "TCL-API": -------------------------------------------------------------- Thanks Leon that does answer my question perfectly. So basically the 7206 with NPE-G1 can handle 4x as many PPS, but all TCL still uses the main CPU, which is a SB-1 @ 700MHz... compared to the 3745's R7000 @ 350MHz... so I can expect (very roughly) double the CPS? And even upgrading or adding new cards to the 7206 would not make any difference?

Could you point me in the direction of any routers that have a better CPU, that would be able to handle say 10x the number of calls?? I'm guessing the 3845 and 3945 would not be much of an improvement either?

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