Hi,
As a rule of thumb, I like to use the default settings for the upstream cards in the Arris 1000 and 1500 CMTSs. But, is there a better way? For example, if I have some stubborn modems that won't connect can I set one card to be sort of a "catch all" that gets modems with less than good signal levels? I guess what I need is a cheat sheet for all of those parameters in the upstream cards:
admin-status up
frequency 29950000 hertz
width 3200000 hertz
power 20 tenths-of-dBmV
input-power-window 60 tenths-of-dB
modulation-profile 1 (number)
slot-size 4 (6.25 uSec ticks)
start-ranging-backoff 2 (2 to this power, 16=>special)
end-ranging-backoff 5 (2 to this power, 16=>special)
start-tx-backoff 3 (2 to this power, 16=>special)
end-tx-backoff 10 (2 to this power, 16=>special)
minimum-map-size 32 slots
maximum-map-size 2048 slots
contention-per-map 32 mini-slots
request-data-allowed disallowed
max-data-in-contention 80 mini-slots
initial-ranging-interval 2000 microseconds
high-priority-threshold 75 (number)
guaranteed-threshold 100 percent
link-trap enabled
alias ""
max-cbr-flows -1 flows (-1 = no limit)
Thanks,
Eric
Hi,
The reason I'l asking is that I have a bnch of modems that do this:
09/27/10 11:04:51 00:13:11:61:bd:e2 DHCP DISCOVER:
DA=ff:ff:ff:ff:ff:ff SA=00:13:11:61:bd:e2
SRC IP=0.0.0.0 DST IP=255.255.255.255
yiaddr=0.0.0.0
09/27/10 11:04:51 00:13:11:61:bd:e2 DHCP OFFER:
DA=00:13:11:61:bd:e2 SA=00:00:24:cc:12:8a
SRC IP=10.0.12.1 DST IP=10.0.12.142
yiaddr=10.0.12.142
09/27/10 11:04:52 00:13:11:61:bd:e2 DHCP REQUEST:
DA=ff:ff:ff:ff:ff:ff SA=00:13:11:61:bd:e2
SRC IP=0.0.0.0 DST IP=255.255.255.255
yiaddr=0.0.0.0
09/27/10 11:04:52 00:13:11:61:bd:e2 DHCP ACK:
DA=00:13:11:61:bd:e2 SA=00:00:24:cc:12:8a
SRC IP=10.0.12.1 DST IP=10.0.12.142
yiaddr=10.0.12.142
09/27/10 11:04:52 00:13:11:61:bd:e2 SID:8106, TFTP Read Request
Adj: +1725 ticks, +8.75dB,
09/27/10 11:04:56 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:04:57 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.50dB,
09/27/10 11:04:57 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:04:58 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.00dB,
09/27/10 11:04:58 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:04:59 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.75dB,
09/27/10 11:04:59 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:00 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.50dB,
09/27/10 11:05:00 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:01 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.50dB,
09/27/10 11:05:01 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:02 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.00dB,
09/27/10 11:05:02 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:03 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.50dB,
09/27/10 11:05:03 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:04 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.00dB,
09/27/10 11:05:04 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
09/27/10 11:05:05 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.75dB,
09/27/10 11:05:05 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
mod ac09/27/10 11:05:06 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.50dB,
09/27/10 11:05:06 00:13:11:61:bd:e2 Sent Rng Resp: Continue, SID 8106
t09/27/10 11:05:07 00:13:11:61:bd:e2 Rcvd Rng Req-> Adj: +8.25dB,
09/27/10 11:05:07 00:13:11:61:bd:e2 Ranging Aborted; Too Many Retries
Thanks,
Eric
Why not correct the RF problem instead of putting a band-aid workaround on it at the CMTS?
Poge
The plant is clean. It worked with the old CMTS. I just need an explanation of why the CM gets so far into the process before it fails every time.
Eric
Hi Eric,
It seems to be RF problem - cable modem is out of range, try to set lower rx power on the upstream card
Regards
Darek
Your plant may be clean, but there would appear to be signal level problems prohibiting these certain modems from obtaining sync. I'd work backwards from the upstream input(s) to figure out where the problem is -- unless it is in the CMTS's array of couplers/connections in the box itself. If I recall, those boxes are full of DC's and jumpers hooking everything together on the inside of the unit. I had one at one time and found several of the internal 'F' connections not even finger tight. Not good. Otherwise, check your combining and ensure your return levels are proper for unity gain over that return leg to hit the CMTS at the designed level -- which does not appear to be happening, hence your problem.
Good luck.
Poge