Hi,
What are they exact commands to see how hard a modem is sending or receiving it's signal. Ihave a lot of modems that to the following.
Some times it comes online but most of the time it gives this results.
Ranging Adjusted - 12 times
07/06/2012 17:33:58 Ranged
07/06/2012 17:34:09 Ranging aborted - Too Many retries
07/06/2012 17:34:29 Initial Ranging
Ranging Adjusted - 12 times
07/06/2012 17:34:29 Ranged
07/06/2012 17:34:40 Ranging aborted - Too Many retries
07/06/2012 17:35:08 Initial Ranging
07/06/2012 17:35:08 Ranging Adjusted
07/06/2012 17:35:08 Ranged
07/06/2012 17:35:09 Ranging missed
Ranging Adjusted - 12 times
07/06/2012 17:35:09 Ranged
07/06/2012 17:35:20 Ranging aborted - Too Many retries
07/06/2012 17:35:36 Initial Ranging
Ranging Adjusted - 12 times
07/06/2012 17:35:36 Ranged
07/06/2012 17:35:47 Ranging aborted - Too Many retries
07/06/2012 17:36:11 Initial Ranging
Hi,
You're problem is with the upstream on your plant. Either there is too much noise or you need to lower the padding on your LEs. The modems can't swim upstream hard enough to get to the CMTS.
emkowale
How can i play with the padding? I can be done trough snmp but i cant find the right commando to do this.
Ranging was aborted for bad receiver data.
/
Channel Status Speed In Octets Mod Profile Frequency Power Window
------- ------- --------- ---------- ----------- --------- ----- ------
4 up 5120000 10143123 1 33000000 100 60
5 up 5120000 31571602 1 33000000 100 60
6 up 5120000 41730510 1 33000000 50 60
U seem to got 33MHz on every upstream connector?
Are these levels oke?
Upstream Channel : 1
Upstream Frequence : 33000000
Downstream Frequence : 141000000 Hz
Signal noise ratio : 36.7 dB
RX power : -7.9 dBmV
TX power : 58 dBmV
From your post, not sure what cmts your using or needing help with, but from that last post, looking to be a registered cable modem, the upstream or tx power level is too high. if you could remove some return attenuation so it's around 48 or 50, it will run better and have less chance of going up and down. with summer time here, the return has more attenuation and if that level of 58 was done during the night, come hot mid day the modem level would max if not already trying to reach the cmts receiver and fall out it's range level. are the return nodes clipping? all modems have an average transmit level close to 60? you may need to lower the receive level on the cmts or take away some padding at the head end if that's the case
Modems are connecting and disconnecting,
A other modem specs
Noise rate 31.2
Rx power -16
Tx power 58.0
How can i lower the receive level?
[cmts] upstream-list# show
Upstream list
Channel Status Speed In Octets Mod Profile Frequency Power Window
------- ------- --------- ---------- ----------- --------- ----- ------
4 up 2560000 753080 1 16000000 50 60
5 up 320000 482308 1 33000000 50 60
6 up 2560000 8597051 1 8000000 50 60
7 up 2560000 3749785 1 8000000 70 60
8 down 0 0 1 10750000 260 60
9 down 0 0 1 10750000 260 60
10 down 0 0 1 10750000 140 60
11 down 0 0 1 10750000 260 60
Is this oke?
golden levels for you are receive level of 0 +/- 10 and transmit between 40 and 50. get them there and you will be all set.
docsis spec is receive 0 +/- 15, yours are out of spec and hence issues your dealing with modems go up and down or flap, etc..
lower your power level from 50 to 0 for example. 50 = 5.0 I assume. if you have pads, remove a 6 pad. nodes should be balanced, lowering levels is just a quick fix
Oke, so there s something in the cable network, most of the modems are out of spec. Whe will send a technican to replace all amplifiers and to some balancing on the cables.
Is this a new system that was just installed or they haven't done work on the return in a long time? you need to consider that when they balance the return with a carrier it shouldn't be with one of those narrow single or dual carriers the tech's use to check continuity, you need a 3.2 or 6.4Mhz wide data carrier, not video. a diag cable modem would work best because they could create a 3.2Mhz wide constant carrier with 16Qam modulation. this would be best when they setup the return on each node. also pad according at the head end so it's around zero or so going into the cmts receiver.
how many cable modems are on this cable plant? hfc or just coax? upstream modulation from the modems, qpsk or 16Qam? assume it's a 3.2Mhz wide carrier. I would lower the cmts receive levels to zero for now while the tech's work out the plant side of things, that should help to keep the modems online
Can somebody help me with the configuration of a Arris/Nortel 1000? It has 4 Upstream channels. Whe have some problems in the plant but i want to know if the config is oke.
//you dont have to do it for free//
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