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.
If the problem is in the RF, which steps could take to help ? use qam16 instead quam64 ? change the bandwidth channel ?
Thanks for any help
Cable modem(s).... is this on just one upstream or all your upstream ports? what is the snr and physical delay?
the snr is where you need to look before making the change from modulation and bandwidth. the modems are timing out. your snr should be in the upper 20's . what modulation profile do you use?
~Carl
I have this errors in all Upstream, my SNR is > 42 and MER > 30 in US1 and MER > 35 the others.
I am using the modulation profile 29
cable modulation-profile 29 request AdvPhy ATDMA 1 1536
cable modulation-profile 29 request AdvPhy preamble-type qpsk1
cable modulation-profile 29 request 0 16 0 8 qpsk scrambler 338 no-diff 64 fixed
cable modulation-profile 29 initial AdvPhy ATDMA 1 1536
cable modulation-profile 29 initial AdvPhy preamble-type qpsk1
cable modulation-profile 29 initial 5 34 0 48 qpsk scrambler 338 no-diff 640 fixed
cable modulation-profile 29 station AdvPhy ATDMA 1 1536
cable modulation-profile 29 station AdvPhy preamble-type qpsk1
cable modulation-profile 29 station 5 34 0 48 qpsk scrambler 338 no-diff 384 fixed
cable modulation-profile 29 advPhyS AdvPhy ATDMA 1 1536
cable modulation-profile 29 advPhyS AdvPhy preamble-type qpsk1
cable modulation-profile 29 advPhyS 12 78 11 8 64qam scrambler 338 no-diff 152 shortened
cable modulation-profile 29 advPhyL AdvPhy ATDMA 8 1504
cable modulation-profile 29 advPhyL AdvPhy preamble-type qpsk1
cable modulation-profile 29 advPhyL 16 220 0 8 64qam scrambler 338 no-diff 304 shortened
cable modulation-profile 29 advPhyU AdvPhy ATDMA 1 1536
cable modulation-profile 29 advPhyU AdvPhy preamble-type qpsk1
cable modulation-profile 29 advPhyU 12 78 0 8 64qam scrambler 338 no-diff 152 shortened
I currently disabled the BPI and still having litlle cuts, but just for a few seconds. If I enable BPI the cuts are longer, like 2/3 minutes.
Thanks for your help !!!
Please double check, I have yet to see and snr better than 42 on a cable plant. a test bench, yes. but hfc plant, no.
Here's 2 of my mod profiles with atdma. the 1st is default and the second is one I made for noisy plant.
you might want to check your settings for:
cable upstream 1/0 channel-type atdma
cable upstream 1 channel-width 6400000
cable upstream 1 frequency 13200000
cable upstream 1 pre-equalization
cable upstream 1 physical-delay automatic
cable upstream 1 spectrum-group group1
cable upstream 1 ingress-canceller enable
cable upstream 1/0 data-backoff 2 8
cable upstream 1/0 range-backoff 2 8
cable upstream 1 power-level 0
cable upstream 1/0 minislot-size 2
cable upstream 1 invited-range-interval 10000
no cable upstream 1 range-forced-continue
no cable upstream 1 range-power-override
cable upstream 1 map-interval 2000
cable upstream 1/0 modulation-profile 255
cable upstream 1 rate-limit
cable upstream 1/0 force-frag 0
cable upstream 1 snr-offset 10
no cable upstream 1 shutdown
no cable upstream 1/0 shutdown
cable upstream 1/1 channel-type atdma
cable upstream 1/1 data-backoff 2 8
cable upstream 1/1 range-backoff 0 4
cable upstream 1/1 minislot-size 2
cable upstream 1/1 modulation-profile 255
cable upstream 1/1 force-frag 0
no cable upstream 1/1 shutdown
BSR2k#sh cable modulation-profile 201
Cable Modulation Profile 201
+--------------+------+------+------+------+------+------+------+------+
| | 1 | 3 | 4 | 5 | 6 | 9 | 10 | 11 |
| IUC | Req | Init | Per | Short| Long | Adv | Adv | Adv |
| | | Maint| Maint| Data | Data | Short| Long | UGS |
+--------------+------+------+------+------+------+------+------+------+
Modulation qpsk qpsk qpsk XXXX XXXX 64qam 64qam 64qam
Diff Encoding OFF OFF OFF XXXX XXXX OFF OFF OFF
Preamble Len 64 640 384 XXXX XXXX 64 128 128
FEC Err CRC 4 10 10 XXXX XXXX 16 16 16
FEC CW Len 16 34 34 XXXX XXXX 75 219 219
Scrambler Seed 50 338 338 XXXX XXXX 6236 6378 6378
Max Burst 0 0 0 XXXX XXXX 3 0 0
Guard Time 8 48 48 XXXX XXXX 8 8 8
Last Codeword FIXED FIXED FIXED XXXX XXXX SHORT SHORT SHORT
Scrambler ON ON ON XXXX XXXX ON ON ON
Intlv Depth 1 1 1 XXXX XXXX 1 1 1
Intlv Blk Sz 1536 1536 1536 XXXX XXXX 1536 1536 1536
Preamble Type QPSK0 QPSK0 QPSK0 XXXX XXXX QPSK1 QPSK1 QPSK1
SCDMA Spreader OFF OFF OFF XXXX XXXX OFF OFF OFF
Codes Subfrm 0 0 0 XXXX XXXX 0 0 0
Intlv Stp Sz 0 0 2 XXXX XXXX 0 0 0
TCM Encoding OFF OFF OFF XXXX XXXX OFF OFF OFF
Channel Type atdma atdma atdma XXXX XXXX atdma atdma atdma
########################################################################
cable modulation-profile 206
iuc reque atdma qpsk 4 16 fixed 0 on 0x32 off qpsk0 64 1 1536 0 off 0 off
iuc initi atdma qpsk 10 34 fixed 0 on 0x152 off qpsk0 640 1 1536 0 off 0 off
iuc stati atdma qpsk 10 34 fixed 0 on 0x152 off qpsk0 384 1 1536 2 off 0 off
iuc a-sho atdma 8qam 16 75 short 3 on 0x185c off qpsk1 128 1 1536 0 off 0 off
iuc a-lon atdma 8qam 16 219 short 0 on 0x18ea off qpsk1 192 1 1536 0 off 0 off
iuc a-ugs atdma 64qam 16 219 short 0 on 0x18ea off qpsk1 192 1 1536 0 off 0 off
I have a few CM (like 60) in total , using the 4 US ports, the hfc design is deep fiber, and using Cadant C3 as CMTS, an dmy values of SNR and MER are like I say before.
Cable1/0 Upstream 0.0
Frequency 28.0 MHz,Channel-Width 3.200000 MHz
Channel-type: ATDMA
SNR 42.0 dB, MER 30.8 dB
Cable1/0 Upstream 1.0
Frequency 31.200000 MHz,Channel-Width 3.200000 MHz
Channel-type: ATDMA
SNR 50.0 dB, MER 42.7 dB
Cable1/0 Upstream 2.0
Frequency 34.400000 MHz,Channel-Width 3.200000 MHz
Channel-type: ATDMA
SNR 50.0 dB, MER 42.9 dB
Currently having some issues to be fixed today in the US3
Cable1/0 Upstream 3.0
Frequency 37.600000 MHz,Channel-Width 3.200000 MHz
Channel-type: ATDMA
SNR 33.2 dB, MER 27.3 dB
3 node max in every US.
Thanks
This does suggest an upstream issue. I actually run daily reports off my CMTS syslogs for "ranging retries exhausted" issues.
Can you query the CMTS for the the CM's US SNR at the CMTS?
Frank