CMTS Archives

1 10, 2012

Cable Modem Registration | A Second Look

Mia Colabrese2021-08-17T10:17:11-04:00October 1st, 2012|

DOCSIS Cable Modems Registration Process Even the most interesting man in the world enjoy's the DOCSIS cable modem registration process, so it is worth a second look. It is one of the most popular topics because it covers a wide range of how DOCSIS works, from physical layer to Internet protocol (IP) layer. It is therefore worthy of an encore article with more depth and an update to include DOCSIS 3.0. During the cable modem registration process it is important to understand that three (3) different levels of

17 09, 2012

DOCSIS Codeword Errors | What you should know

Mia Colabrese2024-04-19T10:18:35-04:00September 17th, 2012|

Calculating... Calculating... DOCSIS Codeword Errors - You will likely see them DOCSIS correctable codeword errors and uncorrectable codeword errors are available as a metric in most cable operator monitoring tools and Operations Support Systems (OSS). The monitoring tools and OSS generally provide data and dashboards for users to monitor overall network health and then identify a problem when it occurs. Metrics like codeword errors are extracted directly from DOCSIS CMTSs using Simple Network Management Protocol (SNMP) or Internet Protocol Detail Records (IPDR), the later being preferred due to

29 02, 2012

Impact of Impulse Noise on Adaptive Pre-Equalization

Mia Colabrese2021-11-24T09:26:04-05:00February 29th, 2012|

For those of you who have attended my seminars you are familiar with adaptive pre-equalization in cable modems (if not I'll explain it in detail momentarily). Also, if you have done any amount of RF plant troubleshooting you are certainly familiar with Impulse noise (again, I'll cover this too). But if you are like me, I never knew that the two topics were co-related.

28 09, 2011

BTR | Rollouts Continue as DOCSIS 3.0 Matures

Mia Colabrese2022-02-15T16:04:02-05:00September 28th, 2011|

The following article just released by Broadband Technology Report was written by Carl Weinschenk. A number of us from the industry contributed to Carl's piece, but it is a nice high-level summary article on the status of DOCSIS 3.0. Below you will find a snippet of the article with a link to the BTR website for the complete read. Enjoy. Rollouts Continue as DOCSIS 3.0 Matures There are just two areas of concern as the rollout of DOCSIS 3.0 continues: the upstream and the downstream. Observers seem satisfied

21 09, 2011

Cable Modems init(r1) init(r2) Why are they stuck?

Mia Colabrese2021-08-20T09:21:27-04:00September 21st, 2011|

Cable Modems init(r1) init(r2), DOCSIS Cable Modems going offline? DOCSIS Cable Modems init(r1) init(r2) are stuck or offline! Many of us have been there before - one or more DOCSIS cable modems init(r1) init(r2) stuck in one of numerous "init()" conditions - how do we interpret these messages and what do we do? A recent reader wrote in and had just this problem. DOCSIS cable modems going offline and getting stuck in "R1" or "R2" condition, or Cable Modems init(r1) init(r2), because these are the status conditions displayed on the DOCSIS CMTS

15 09, 2011

Which is Best CMTS or EOC – Ethernet over Coax?

Mia Colabrese2011-09-15T18:24:40-04:00September 15th, 2011|

Interesting post from fellow DOCSIS technologist on CMTS vs. EOC (Ethernet over Coax). Check out the post and his blog.

5 09, 2011

Top 10 DOCSIS 3.0 Terms You Need to Know

Mia Colabrese2021-08-17T13:31:08-04:00September 5th, 2011|

This is the speak you need to know when talking DOCSIS 3.0 to any DOCSIS Engineer or specialist. It is important that you learn the full name, in many cases the acronym and also what value the particular terminology plays in a DOCSIS 3.0 network as it will likely be crucial in troubleshooting tough-to-diagnose DOCSIS impairments.

31 07, 2011

IPv6 and PC Provisioning in a DOCSIS Network

Mia Colabrese2021-08-18T10:01:08-04:00July 31st, 2011|

With IPv6 on the way in a number of MSO (Multi-System Operator) networks, I have received numerous questions lately about how home devices such as routers and PCs attached to DOCSIS cable modems will get their IP addresses. Will cable operators suddenly start issuing IPv6 IP addresses to their customers? Will you as a subscriber need to upgrade your equipment to support IPv6? Or does the cable modem act as a Network Address Translation (NAT) device and hand-out IP address to each device attached to it? These are some very good questions and the answers are addressed in the DOCSIS specification as I will outline.

24 06, 2011

DOCSIS T1, T2, T3, and T4 Timeout Descriptions

Mia Colabrese2022-06-20T20:55:33-04:00June 24th, 2011|

This is a handy summary of the various timeout errors you will find in a DOCSIS network. T3 and T4 timeouts are described in much more detail elswhere in this blog, however this post provides a high level overview of the various timeouts as a reference.

20 04, 2011

Undocumented Cisco CMTS Commands

Mia Colabrese2021-11-24T09:24:55-05:00April 20th, 2011|

Every now and then you find a very useful URL. If you are a Cisco CMTS user then you find some of the undocumented commands on this site usefull: