Comments on: DOCSIS and Cable Modems – How it works :: Anatomy of a Burst http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/ Wed, 21 Jul 2010 23:42:37 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: Brady http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/comment-page-1/#comment-64 Brady Wed, 26 May 2010 01:56:46 +0000 http://bradyvolpe.com/?p=162#comment-64 Hi Aditya, The IUCs are an output of the Burst Profile or modulation profile defined in the running-config on a Cisco CMTS. Cisco has a lot of great online documentation for modifying their modulation profiles depending upon which CMTS model you have and which IOS you are running. I recommend Goggling this topic and you should come up to speed rather quickly. But you absolutely must have administrator access to the CMTS. This is not something that can be done from the cable modem (i.e. if you are trying to hack in :-). Regards, -Brady Hi Aditya,

The IUCs are an output of the Burst Profile or modulation profile defined in the running-config on a Cisco CMTS. Cisco has a lot of great online documentation for modifying their modulation profiles depending upon which CMTS model you have and which IOS you are running. I recommend Goggling this topic and you should come up to speed rather quickly. But you absolutely must have administrator access to the CMTS. This is not something that can be done from the cable modem (i.e. if you are trying to hack in :-) .

Regards,
-Brady

]]> By: Aditya http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/comment-page-1/#comment-63 Aditya Tue, 13 Apr 2010 04:35:44 +0000 http://bradyvolpe.com/?p=162#comment-63 can we force cmts to select "burst profile" via IUCs ? If so which command is there for Cisco CMTS ? can we force cmts to select “burst profile” via IUCs ?
If so which command is there for Cisco CMTS ?

]]> By: Brady http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/comment-page-1/#comment-62 Brady Tue, 08 Dec 2009 15:48:11 +0000 http://bradyvolpe.com/?p=162#comment-62 Okinawajoe, For DOCSIS 1.x and 2.0 timing sources are not easily supported for DOCSIS CMTSs. In DOCSIS 3.0 Modular CMTS architectures, they do become mandatory and greatly improve the timing of the architecture. Symmetricom is a provider of DOCSIS Timing References for DOCSIS 3.0 CMTSs. I will cover this in more detail when I pick back up the DOCSIS 3.0 Tutorial series. Regards, -Brady Okinawajoe,

For DOCSIS 1.x and 2.0 timing sources are not easily supported for DOCSIS CMTSs. In DOCSIS 3.0 Modular CMTS architectures, they do become mandatory and greatly improve the timing of the architecture. Symmetricom is a provider of DOCSIS Timing References for DOCSIS 3.0 CMTSs. I will cover this in more detail when I pick back up the DOCSIS 3.0 Tutorial series.

Regards,
-Brady

]]> By: okinawajoe http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/comment-page-1/#comment-61 okinawajoe Tue, 01 Dec 2009 16:00:25 +0000 http://bradyvolpe.com/?p=162#comment-61 Looking forward to reading more on A-TDMA ... question ... is an external timing source required for A-TDMA? I seem to remember this being the case (highly suggested?) in a Symmetricom white paper. Looking forward to reading more on A-TDMA … question … is an external timing source required for A-TDMA? I seem to remember this being the case (highly suggested?) in a Symmetricom white paper.

]]> By: Brady http://bradyvolpe.com/docsis-101/docsis101_anatomy-of-a-burst/comment-page-1/#comment-60 Brady Mon, 23 Feb 2009 13:54:59 +0000 http://bradyvolpe.com/?p=162#comment-60 Dave, Good catch. I made the correction already. I spend too much time on Cisco CMTSs where the standard minimum mini-slot time is two-ticks or 12.5 usec. Thanks for giving feedback on my error. Nothing worse than mis-information. Regards, -Brady Dave,

Good catch. I made the correction already. I spend too much time on Cisco CMTSs where the standard minimum mini-slot time is two-ticks or 12.5 usec. Thanks for giving feedback on my error. Nothing worse than mis-information.

Regards,
-Brady

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