TCL CPU usage

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    This document was generated from CDN thread

    Created by: Mark Alliban on 15-11-2012 04:08:28 AM
    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?
     

    Subject: RE: TCL CPU usage
    Replied by: Mark Alliban on 15-11-2012 06:33:55 AM
    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.
     

    Subject: RE: TCL CPU usage
    Replied by: Raghavendra Gutty Veeranagappa on 15-11-2012 06:01:53 AM
    Hi Mark,
     
    For the higher number of concurrent calls requires more memory, try playing less media files so that less memory is being used.
     
    Thanks,
    Raghavendra

    Subject: Re: New Message from Raghavendra Gutty Veeranagappa in Voice Gateway API (V
    Replied by: LEON MCCALLA on 15-11-2012 08:04:48 AM
    I get close to 1000 calls on 3745s with c3745-ipvoice_ivs-mz.124-15.T14.bin  at 80-90%CPU but I’m using a tandem TCL script. once I start using larger TCL scripts, the CPU gets higher and calls drop..

    Leon.



    From: Cisco Developer Community Forums
    Sent: Thursday, November 15, 2012 7:01 AM
    To: cdicuser@developer.cisco.com
    Subject: New Message from Raghavendra Gutty Veeranagappa in Voice Gateway API (VGAPI) - TCL-API: RE: TCL CPU usage

    Raghavendra Gutty Veeranagappa has created a new message in the forum "TCL-API": -------------------------------------------------------------- Hi Mark,

    For the higher number of concurrent calls requires more memory, try playing less media files so that less memory is being used.

    Thanks,
    Raghavendra
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    Subject: RE: TCL CPU usage
    Replied by: Mark Alliban on 15-11-2012 08:12:47 AM
    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?
     

    Subject: Re: New Message from Mark Alliban in Voice Gateway API (VGAPI) - TCL-API: R
    Replied by: LEON MCCALLA on 15-11-2012 10:04:48 AM
    trim the fat on the TCL to improve your CPS and/or total calls.

    Leon

    From: Cisco Developer Community Forums
    Sent: Thursday, November 15, 2012 9:12 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": -------------------------------------------------------------- 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?

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    Subject: RE: TCL CPU usage
    Replied by: Yaw-Ming Chen on 15-11-2012 10:25:01 AM
    Mark Alliban:
    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?
     

     
    For the hardware performance you may like to ask Cisco TAC or product manager.
    One thing like to share is that when the call is connected and no long need Tcl to perform any feature we can handoff call to IOS doing this can reduce active Tcl session and cpu ussage. This may not answer your question but just like to point out.
    Thanks !

    Subject: Re: New Message from Mark Alliban in Voice Gateway API (VGAPI) - TCL-API: R
    Replied by: LEON MCCALLA on 15-11-2012 11:10:48 AM
    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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    Subject: RE: TCL CPU usage
    Replied by: Mark Alliban on 15-11-2012 10:12:47 AM
    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?
     

    Subject: RE: TCL CPU usage
    Replied by: Mark Alliban on 16-11-2012 03:49:11 AM
    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?
     

    Subject: Re: New Message from Mark Alliban in Voice Gateway API (VGAPI) - TCL-API: R
    Replied by: LEON MCCALLA on 16-11-2012 09:59:48 AM
    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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