I took over a cable plant about 1 year ago, they only had Docsis 1.X and 2.0 running. We wanted to upgraded to DOCSIS 3.0. Our CTMS and cable modems we got seem to work fine for 3.0. But I'm noticing in our plant that some DOCSIS 3.0 modems don't bond all 5 channels like they should. Reading over the DCOSIS 3.0 specs it looks like the frequency range is 108 - 1ghz.
My Frequency are as follows
99
105
111
117
237
I am wondering if my frequency are too low, and if i have too much of gap between 117 and 237. I know the 108-1ghz is not a hard rule because i get some modems that will bond all 5 channels, most of them only bond 99-117. Just wondering what other cable operators have picked.
Most D3 modems already deployed are either 4 or 8 channel bonding devices, so it's normal to see some bond on 4 and others using more. Keep in mind that most docsis 3 modems have one or two block tuners, usually 32 MHz wide. (e.g. see the spec sheet for the Cisco/SA DPC3212 8 channel modem - http://www.cisco.com/en/US/prod/collateral/video/ps8611/ps8675/ps8682/70...). What this means is groups of 4 bonded channels must fit within a 32 MHz span. Your first four channels only cover 24 MHz so that's okay. 8 channel modems should be able to place their second tuner up on 237 MHz, so you should see 5 channel bonding for those units. As far as I remember it was fine to place the second set of channels as far away as desired from the first, so long as the second set of channels was again kept within a 32 MHz span. But just to make sure - if you have an 8 channel modem that's only bonding on 4, I'd look at the specs to see if the tuner config allows for the skip. (The moto modems I worked with always did, but I'm unfamiliar with other brands).
Yeah I'm using moto 6141. Some bond all 5, most bond the 4. It just caught me off guard that the specs for 3.0 say 108mhz, but the modems obviously work below that. I thought maybe the modems are having a hard time bonding that low.
If possible, keep your DOCSIS frequencies contiguous. As others have stated, having a wide gap can cause problems.
To be 100% safe, I would recommend :
* For 4X tuner modems, keep all the channels contiguous, and in the range 108-870MHz
* For 8X tuner modems, keep all the channels within 60MHz, and in the range 108-1002MHz
Refer to DOCSIS MULPI spec document, Annex E. CLAB-6M-004, CLAB-6M-008 etc.
Most modems are capable of more, but it may require you to setup custom rcc templates, and this is something you want to avoid at all costs!
is Avalon?