Docsis chat

Hi all,

Does anybody know how we can block traffic between hosts behind cable modems connected to the same Arris C3 CMTS? And could we define it based on IP subnet or protocol?

Regards,
Astrit,

Hi all,

Is there anyone who can tell me what the values of SNR and CNR must be to have an good signal.

And if my levels are bad, what will happen?
e.g. will my upstream drop from 16qam to qpsk, or will it yust be dead?

I now have: SNR 22.6dB and CNR 20dB. I expect thats a bit low ?

thanks,
W.

Hi all,

During testing, i've discovered that my US is in QPSK, although my CMTS modulation profile is:
cable modulation-profile 222 request 0 16 0 22 16qam scrambler 152 no-diff 32 fixed qpsk1 1 2048
cable modulation-profile 222 initial 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048
cable modulation-profile 222 station 5 34 0 48 16qam scrambler 152 no-diff 64 fixed qpsk1 1 2048
cable modulation-profile 222 a-short 4 76 7 22 16qam scrambler 152 no-diff 64 shortened qpsk1 1 2048

hi all,

in test setup my docsis 2.0 speeds are : DS --> 37Mbits/s and US --> 305kbits/s

DS i'm satisfied, but US is a disaster...

Anyone an idee ??

Here my CM config file (CM = Scientific Atlanta Webstar)

Main
{
NetworkAccess 1;
MaxCPE 2;
UsServiceFlow
{
UsServiceFlowRef 2;
QosParamSetType 7;
TrafficPriority 1;
MaxRateSustained 30000000;
MaxTrafficBurst 65224;
MinReservedRate 25000000;
}
DsServiceFlow
{

I am a cable operator looking for someone who could set up an all inclusive solution for provisioning, etc. to launch my Arris 1000 CMTS in a new system. If you would send me your info at office@mptelco.com. Looking to move quickly. Thanks.

Hello DOCSIS community,

I have a strange problem on some of the Terayon Bluewave CMTSs. These boxes have been in service for a couple of years now, without major problems. I use DOCSIS2.0 modems and configurations only, I don't have any older modems. The thing that happens is, some of the CPEs cannot access the DNS servers. Here are the simptoms:

- modems register without problems
- CPEs receive their IPs and other stuff from DHCP no problem
- CPEs CAN ping anything on internet (based on IP only)
- CPEs CANNOT resolve any FQDN

The C3 logs show

FEB 01 09:25:30: %C3-5-R102.0: Retries exhausted for polled CM - MAC Addr: 001a.6660.8174
FEB 01 09:25:30: %C3-5-R104.0: Failed to receive Periodic RNG-REQ from modem (SID 46),timing-out SID.
FEB 01 09:29:33: %C3-5-R101.0: No Ranging Requests received from POLLED CM (CMTS generated polls). (16 logged)
FEB 01 09:29:33: %C3-5-R102.0: Retries exhausted for polled CM - MAC Addr: 001a.6660.8174
FEB 01 09:29:33: %C3-5-R104.0: Failed to receive Periodic RNG-REQ from modem (SID 46),timing-out SID.

and the modem time out.

To date I am familiar with the Arris TM5XX and SA Webstar series eMTA being used in the US.

Any operators in the US using Thomson THG-540 for VoIP. If so, what CMTS are using.

Is it available through NCTC?

Hello all,

Getting cable modems to work is a piece of cake for me. Getting Analog Telephone Adapters to work with Asterisk over cable modems is easy for me too. For some reason, I am having troubles with the EMTAs specifically the Arris TM502G. The funny thing is that I have access to Arris and ALL of the documentation. I have the cable modem part working fine. The thing I can't figure out is how to tell the Linux dhcpd.conf to send DHCP option 122 to the cable modem part of the TM502G to trigger the dhcp/tftp process of its MTA. Can anyone give me some clues on this?

We just installed a Arris C3 CMTS and are sending the IF output to a EMCEE Transmiter for our MMDS wireless cable plant. The CMTS does not seem to be outputing enough IF to allow the transmitter to come on line fully. Any ideas?