Quote:
Originally Posted by everyday
Which was already common knowledge but thanks for the clarification  |
AFAIK this is only common knowledge as the "default sample interval" on Cisco CMTS and is in fact configurable on each chassis(or even linecard) between 1 and 30minutes.
Additionally there are many more configurable parameters including "average sampling rate frequency", "default sliding window period of 6hrs" and a default "Penalty Period" that defaults to 7 days!
Remember that STMv1.3 also has a 40 enforcement rule limitation and you require 1 rule for upstream with each service tier QOS and again for downstream, with potentially different QOS for residential & business classes and throw in various legacy tiers for mixed mode DOCSIS 1.x and DOCSIS 3 CM's then it's quite possible the combinations could exceed the available 40 rule limit!
While it makes administrative sense to apply a common configuration I've not yet seen any authoritative NTL/VM statement in last decade+ that actually stipulates what IOS version(and thus STM version - because STMv1.2 only had a 20 enforcement rule limit), linecard type, or specific chassis configuration is in use across all the areas?
Furthermore in some tests I performed sporadically attempting to saturate both down/upstream on occasions over a couple of previous years with some discussion with Igni I raised two hypotheses that basically potentially predicted that VM may well disable rule enforcement on mac domain basis just prior,during and immediately after major re-segmentation in order to load-balance prior to re-instating STM!
I'm still awaiting a conclusive answer or plausible counter to those theories so would welcome any alternative explanations via this thread?
In the unlikely event anyone else is at all interested in the methodology involved then here's an example Cisco reference >
Subscriber Traffic Management for the Cisco CMTS Routers
As a minor aside, along with copious DOCSIS tutorials I found this Cisco paper (a tad aged and USA DOCSIS centric and thus not euroDOCSIS) which is really good foundation document (IMHO) >
CAPACITY PLANNING AND DOCSIS TRAFFIC ENGINEERING