Hi.
We're currently deploying high upstream bandwidth subscriptions on our UBR10k using the Cisco guidelines here:
http://www.cisco.com/en/US/docs/ios/cable/configuration/guide/cmts_upstr...
We do however how a large number of 7246VXRs with either NPE-400 CPU cards or C-series cable cards which does not support the new features. Does anybody have some solid tips on providing higher bandwidth on the older Cisco Cable cards ?
We're trying to reach 3 Mbps pr modem.
I'm having issues with the link you posted.
First starting point would be upstream channel widths and modulation profiles. If your not already using 3.2 wide channels and 16 qam upstream that certainly would be the first option.
Its not just the CMTS that you have to be concerned with, the age and type of docsis modems deployed affect other options to using even a higher order modulation profile as well as plant conditions.
You can also look at CMTS channel statistics to see if you have basic congestion issues. If you want you can email me directly at proairpass@yahoo.com, from there I'll reply from my business email account and give you more detailed info.
I do contract DOCSIS engineering and consulting services.
-Tom
Thanks for the reply
I am already using the Max available channel width for the older cards (3.2) and using QAM16 - I looking for upstream parameters that can be tweaked to archive higher pr. modem transfer speeds. Our plants are generally in excellent shape - with U cards we can utilize 6.4 Mhz/Qam64 without issues :) so I'm pretty confident that all I need is the right combo of tweaks to the upstream parameters on the CMTS and the settings in the modem files. The modems are all Docsis2.0 Motorola modems SB5100, SB5101 etc.
Tweaking the settings in the modem file for max burst and max concatination burst seem to have little effect.
Here's the cisco link for optimizing the throughput on U and 5x20 cards.
http://www.cisco.com
/en/US/docs/ios/cable/configuration/guide/cmts_upstream_rate_adapt.html