Quote:
Originally Posted by whydoIneedatech
NTL have a lower limit than Telewest and are still stable.
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Depends on the area and modulation. Ex-CWC areas need a higher SNR than original ntl and Telewest, however Langley ntl and Telewest have identical SNR requirements as they are the same equipment either end of the network.
I wasn't talking about any limits on troubleshooting guides or the documents you might have I was talking about operational limits from experience and the standards.
I suspect the 26dB you refer to refers to 64QAM original ntl downstreams. Neither ex-CWC nor 256QAM downstreams will be happy at 26dB. 256QAM just won't happen and ex-CWC will be showing errors even on 64QAM.
The power is irrelevant to the SNRs, and the guidelines you copy/pasted above while they might be what is aimed for are not required. On Telewest and original ntl so long as network is clean modems will be quite happy to +/- 15dBmV receive power, Bromley -17dBmV - +13dBmV on 64QAM and -13dBmV - +17dBmV on 256QAM.
BTW The ntl Langley and Telewest networks run identical kit. Telewest just took their 'recommended' power straight from the DOCSIS specs while ntl apparently picked theirs from a hat. I'm sure in their dreams they could run every modem on their network within a 3dBmV power range but in reality not going to happen.