Comments on: DOCSIS 3.0 Tutorial – CMTS Architecture http://volpefirm.com/docsis-3-0/docsis3_architecture/ A Technical Communications Company Wed, 16 May 2012 06:51:01 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Branco http://volpefirm.com/docsis-3-0/docsis3_architecture/#comment-231 Branco Wed, 21 Dec 2011 09:45:56 +0000 http://bradyvolpe.com/?p=360#comment-231 Hi Cable Guys, Great tutorial Brady ! Thanks a lot, your website helps me so much. In Europe, I see that a French Cable Operator begins to deploy the RF spanning option with MC20x20 instead of rolling new MC3G60 linecards out . By using one DSport per Linecard to spreading four QAM channels over the other four DSports, we have at last 8 Downstream frequencies, but 4 primary downstreams only and 4 serving groups... So what does this RF spanning solution stand for ? It will be better to roll MC3G60 out. I understand that there is a cost-effective choice for the cable operator but the QoS for subscribers won't be great... Hi Cable Guys,

Great tutorial Brady ! Thanks a lot, your website helps me so much.
In Europe, I see that a French Cable Operator begins to deploy the RF spanning option with MC20x20 instead of rolling new MC3G60 linecards out .
By using one DSport per Linecard to spreading four QAM channels over the other four DSports, we have at last 8 Downstream frequencies, but 4 primary downstreams only and 4 serving groups…

So what does this RF spanning solution stand for ?

It will be better to roll MC3G60 out. I understand that there is a cost-effective choice for the cable operator but the QoS for subscribers won’t be great…

]]> By: Agnet http://volpefirm.com/docsis-3-0/docsis3_architecture/#comment-230 Agnet Tue, 13 Jul 2010 02:29:58 +0000 http://bradyvolpe.com/?p=360#comment-230 We like I-CMTS for new introdution. We like I-CMTS for new introdution.

]]> By: Slimjim100 http://volpefirm.com/docsis-3-0/docsis3_architecture/#comment-229 Slimjim100 Tue, 22 Jun 2010 13:24:02 +0000 http://bradyvolpe.com/?p=360#comment-229 Brady, I have had the pleasure to work with I-CMTS, M-CMTS, & hybrid-CMTS. I think that all the different designs have there place and uses and it can come down to many things that will decide your deployment. I know MSO's that deploy M-CMTS & I-CMTS in the same systems and the reason being is capacity in some hub sites over others. I personally like the M-CMTS due to the raw number of QAM’s I have to combine with and the fact I can easily add more QAM’s without setting up more chassis's and this can be a space saver in a crowded head-end. I even have seen customer go the hybrid route where they started with an I-CMTS and added M-CMTS to the CMTS to run additional QAM for other services. It’s not just about cable modems anymore there are so many different services running over the DOCSIS plant you need flexibility. At the end of the day it comes down to needs, budget, and design. -Brian (Slimjim100) Brady,

I have had the pleasure to work with I-CMTS, M-CMTS, & hybrid-CMTS. I think that all the different designs have there place and uses and it can come down to many things that will decide your deployment. I know MSO’s that deploy M-CMTS & I-CMTS in the same systems and the reason being is capacity in some hub sites over others. I personally like the M-CMTS due to the raw number of QAM’s I have to combine with and the fact I can easily add more QAM’s without setting up more chassis’s and this can be a space saver in a crowded head-end. I even have seen customer go the hybrid route where they started with an I-CMTS and added M-CMTS to the CMTS to run additional QAM for other services. It’s not just about cable modems anymore there are so many different services running over the DOCSIS plant you need flexibility. At the end of the day it comes down to needs, budget, and design.

-Brian (Slimjim100)

]]> By: Brady http://volpefirm.com/docsis-3-0/docsis3_architecture/#comment-228 Brady Tue, 22 Jun 2010 12:45:19 +0000 http://bradyvolpe.com/?p=360#comment-228 Stewart, Thanks for feedback on your experience with I-CMTS vs. M-CMTS architectures. I would appreciate this type of feedback from users in live networks. I have experience in networks where trouble occurs and much more in the traditional 6-foot plant. The real test comes from those of you who are living the day-in day-out trials of these architectures in a production environment. So please continue to provide feedback. -Brady Stewart,

Thanks for feedback on your experience with I-CMTS vs. M-CMTS architectures. I would appreciate this type of feedback from users in live networks. I have experience in networks where trouble occurs and much more in the traditional 6-foot plant. The real test comes from those of you who are living the day-in day-out trials of these architectures in a production environment. So please continue to provide feedback.

-Brady

]]> By: stewart http://volpefirm.com/docsis-3-0/docsis3_architecture/#comment-227 stewart Tue, 22 Jun 2010 09:17:24 +0000 http://bradyvolpe.com/?p=360#comment-227 Brady, I've had experience of both, although not naming vendors. When the idea of a M-CMTS was mooted, I didn't fancy it. I still don't. The idea was sold on the basis you could take some of the components and bunch them together-with only the RF parts being in the remote hubsites. This hasn't happened-edge QAM's for VOD are still being used for VOD, and the same is true for DOCSIS. I haven't seen the over lap-yet. I'm not saying the DOCSIS 3.0 I-CMTS is foolproof either-but I think that is down to the ever increasing tech that goes into these boxes. DOCSIS 1.0 was very simple when you look back at it-but insecure and easily hackable as well-that's progress, I suppose :-) When I worked in telco circuit switches, the thing that always screwed you up were the external timing sources-drift will always be a problem-whereas if everything is on the same physical backplane, the problem goes away. Everybody to their own-different vendors will do it different ways but I find it interesting a certain vendor has gone back on it's promise not to build DOCSIS 3.0 cards for its "pizza box" chassis-all down to customer pressure. The easy upgrade path for D1 to D3, definetly, but not as lucrative for the sales people ;-) Brady,
I’ve had experience of both, although not naming vendors. When the idea of a M-CMTS was mooted, I didn’t fancy it. I still don’t. The idea was sold on the basis you could take some of the components and bunch them together-with only the RF parts being in the remote hubsites. This hasn’t happened-edge QAM’s for VOD are still being used for VOD, and the same is true for DOCSIS. I haven’t seen the over lap-yet.
I’m not saying the DOCSIS 3.0 I-CMTS is foolproof either-but I think that is down to the ever increasing tech that goes into these boxes. DOCSIS 1.0 was very simple when you look back at it-but insecure and easily hackable as well-that’s progress, I suppose :-)
When I worked in telco circuit switches, the thing that always screwed you up were the external timing sources-drift will always be a problem-whereas if everything is on the same physical backplane, the problem goes away.
Everybody to their own-different vendors will do it different ways but I find it interesting a certain vendor has gone back on it’s promise not to build DOCSIS 3.0 cards for its “pizza box” chassis-all down to customer pressure. The easy upgrade path for D1 to D3, definetly, but not as lucrative for the sales people ;-)

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