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CMTS PROBLEM / Modems not connecting

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frosti
CMTS PROBLEM / Modems not connecting

I have configured my CMTS BSR1000 below you can see my start-up config but i have one problem non of modems do connect to connect to BSR , i have tried all modems , Motorola , Scientific Atlanta , Thomson , but none of them worked.

In every modem when i log in to see the logs i get every time this error : " SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing "
Want to point one more thing here in Motorola Modem i only have a flash light at recive and never going below to send.

Below you can see my file but don't know what is the problem why my modems want connect to BSR did i miss configured in CMTS something or you guys have any idea.

!
!
hostname dCMTS
!
!
!
service password-encryption
!
!
ip ftp password 7 9fdd8e5fe3d1c885
!
ip name-server 91.187.106.5
ip name-server 91.187.106.10
!
no logging control docsis
logging admin-status unconstrained
logging rate-limit 100 1
logging buffered notifications
logging console errors
!
!
!
!
interface ethernet 0/0
ip address 192.168.1.3 255.255.255.0
ip address 10.0.1.3 255.255.255.0 secondary
no shutdown
!
interface cable 0/0
ip address 10.15.0.1 255.255.0.0
ip address 10.10.0.1 255.255.0.0 secondary
ip helper-address 10.0.1.2
cable helper-address 10.0.1.2 cable-modem
cable helper-address 10.0.1.2 host
no shutdown
no ip mask-reply
no ip unreachables
cable downstream 0 frequency 450000000
cable downstream 0 power-level 480
cable downstream 0 rate-limit
no cable downstream 0 shutdown
cable upstream 0 frequency 55700000
cable upstream 0 channel-width 200000
cable upstream 0 power-level 110
cable upstream 0 pre-equalization
cable upstream 0 rate-limit
no cable upstream 0 shutdown
cable upstream 1 frequency 40000000
cable upstream 1 channel-width 200000
cable upstream 1 power-level -160
no cable upstream 1 shutdown
cable upstream 2 frequency 56000000
cable upstream 2 channel-width 1600000
cable upstream 2 power-level 110
cable upstream 2 pre-equalization
cable upstream 2 rate-limit
no cable upstream 2 shutdown
cable upstream 3 frequency 52300000
cable upstream 3 channel-width 1600000
cable upstream 3 power-level 110
cable upstream 3 pre-equalization
cable upstream 3 rate-limit
no cable upstream 3 shutdown
cable dynamic-service authorization-mode unauthorize
ip dhcp relay information option
cable flap-list trap-enable
cable downstream schedule priority-wfq
no cable wireless downstream modulation qpsk
!
!
!
!
!
!
!
ip route 0.0.0.0 0.0.0.0 192.168.1.1
!
!
!
snmp-server engineid local 800013750300000000000000
snmp-server chassis-id Serial Number: XXX-YY-ZZZZ
snmp-server contact Tom Keske (Tom.Keske@motorola.com)
snmp-server sysname Name not set
snmp-server location Location not set
snmp-server trap rate-limit 100 1
!
!
packet-cable
dqos shutdown
no em shutdown
!
!
ipsec
ipsec shutdown
!
!
session-timeout console 0
session-timeout telnet 5
!
telnet session-limit 8
!
!
!
!
!
!
!
no ssh enable
!
!
no logging trap
no logging snmp-trap
logging facility local7
!
clock timezone utc 23 0 daylightsavings off
!
!
!
!
time-of-day server 192.168.1.3
enable rdn-process
!
!
!
!
!
cable service-class
!
!
MOT#

I really appreciate your help if somebody have any idea why my modems don't connect.

Regards,
Frost

mtntrailseeker
CMTS PROBLEM / Modems not connecting

Couple of posibilities here.

First the log files and the receive LED only blinking indicates that the modem doesn't see any downstream or cant undertsand it if one is present. If the other modems LED's behave the same way check the following.

What is the total forward path loss between the downstream port and the modem? If your hitting the front end of the modem with too much signal +15 and over, then you'll overdrive the receiver.

Do you have any test equipment to see if there is any downstream signal present?

frosti
We did test downstream

We did test downstream signal and it's present its around +16 up to +17.

but still non of modems do not connect

any ideas please what might cause this problem that modems do not connect.

mtntrailseeker
CMTS PROBLEM / Modems not connecting

Lower the downstream level or increase downstream attentuation. The input level of 16 to 17 is too high.

Another person asked about what type (annex) modems your working with. US docsis or euro docsis?

frosti
We work with Eurodocsis

We work with Eurodocsis modems,

Below you can see my interface configuration .

MOT#show controllers cable 0/0

Interface Cable 0/0
BCM3210 revision=0x321056B2
MAC regs 0x80000000, PLX regs 0x0
rx ring entries 1024, tx ring entries 1024, MAP tx ring entries 1024
Rx ring 0x4609D58, shadow 0x460BD68, head 0x460BD68
Tx ring 0x4602D38, shadow 0x45FFD38, Free: head 0x45FFD38, tail 0x4602D2C, Used: head 0x0, tail 0x0
MAP Tx ring 0x4607D48, shadow 0x4604D48, Free: head 0x4605048, tail 0x4605030, Used: head 0x460503C, tail 0x460503C
Rx: framing_err 0, hcs_err 0, no_buffer 0, short_pkt 0
invalid_sid 0, invalide_mac 0, bad_ext_hrd_pdu 0

Cable 0/0 Downstream 0 is up
Frequency 450.000000 MHz, Channel Width 8 MHz, 256-QAM, Symbol Rate 6.952000 Msps
FEC ITU-T J.83 Annex A, R/S Interleave I=12, J=17
Downstream Channel ID: 1
Spectrum Group:

Cable 0/0 Upstream 0 is up
Frequency 55.700001 MHz, Channel Width 0.200000 MHz, 16QAM, Symbol Rate 0.160000 Msps
Spectrum Group:
SNR 0 dBmv
Nominal Input Power Level 110 dBmV
Ranging Backoff (Start 0, End 4)
Ranging Insection Interval (200 ms)
Tx Backoff Start 2, Tx Backoff End 8
Modulation Profile Group 1
Concatenation is enabled
part_id=0x3137, rev_id=0x3
Range Load Reg Size=0x58
Request Load Reg Size=0xE
Minislot Size in number of Timebase Ticks is = 64
Minislot Size in Symbols = 64
Bandwidth Requests = 0x0
Piggyback Requests = 0x0
Invalid BW Requests = 0x0
Minislots Requested = 0x0
Minislots Granted = 0x0
Minislots Size in Bytes = 32, Map Advance (Dynamic): 2455 usecs
UCD Count = 0
Slots 0, NoUWCollNoEnergy 0, FECCorHCS 0, HCS 0
Req 223405544, ReqColl 0, ReqNoise 0, ReqNoEnergy 223405544
ReqData 0, ReqDataColl 0, ReqDataNoise 0, ReqDataNoEnergy 0
Rng 0, RngColl 0, RngNoise 0
FECBlks 0, UnCorFECBlks 0, CorFECBlks 0

Cable 0/0 Upstream 1 is up
Frequency 40.000000 MHz, Channel Width 0.200000 MHz, 16QAM, Symbol Rate 0.160000 Msps
Spectrum Group:
SNR 0 dBmv
Nominal Input Power Level -160 dBmV
Ranging Backoff (Start 0, End 4)
Ranging Insection Interval (200 ms)
Tx Backoff Start 2, Tx Backoff End 8
Modulation Profile Group 1
Concatenation is enabled
part_id=0x3137, rev_id=0x3
Range Load Reg Size=0x58
Request Load Reg Size=0xE
Minislot Size in number of Timebase Ticks is = 64
Minislot Size in Symbols = 64
Bandwidth Requests = 0x0
Piggyback Requests = 0x0
Invalid BW Requests = 0x0
Minislots Requested = 0x0
Minislots Granted = 0x0
Minislots Size in Bytes = 32, Map Advance (Dynamic): 2455 usecs
UCD Count = 0
Slots 0, NoUWCollNoEnergy 0, FECCorHCS 0, HCS 0
Req 223413415, ReqColl 0, ReqNoise 0, ReqNoEnergy 223413415
ReqData 0, ReqDataColl 0, ReqDataNoise 0, ReqDataNoEnergy 0
Rng 0, RngColl 113265944, RngNoise 0
FECBlks 0, UnCorFECBlks 0, CorFECBlks 0

Cable 0/0 Upstream 2 is up
Frequency 56.000000 MHz, Channel Width 1.600000 MHz, 16QAM, Symbol Rate 1.280000 Msps
Spectrum Group:
SNR 0 dBmv
Nominal Input Power Level 110 dBmV
Ranging Backoff (Start 0, End 4)
Ranging Insection Interval (200 ms)
Tx Backoff Start 2, Tx Backoff End 8
Modulation Profile Group 1
Concatenation is enabled
part_id=0x3137, rev_id=0x3
Range Load Reg Size=0x58
Request Load Reg Size=0xE
Minislot Size in number of Timebase Ticks is = 8
Minislot Size in Symbols = 64
Bandwidth Requests = 0x0
Piggyback Requests = 0x0
Invalid BW Requests = 0x0
Minislots Requested = 0x0
Minislots Granted = 0x0
Minislots Size in Bytes = 32, Map Advance (Dynamic): 2455 usecs
UCD Count = 0
Slots 0, NoUWCollNoEnergy 0, FECCorHCS 0, HCS 0
Req 928910151, ReqColl 0, ReqNoise 0, ReqNoEnergy 928910151
ReqData 0, ReqDataColl 0, ReqDataNoise 0, ReqDataNoEnergy 0
Rng 0, RngColl 113265944, RngNoise 0
FECBlks 0, UnCorFECBlks 0, CorFECBlks 0

Cable 0/0 Upstream 3 is up
Frequency 52.299999 MHz, Channel Width 1.600000 MHz, 16QAM, Symbol Rate 1.280000 Msps
Spectrum Group:
SNR 0 dBmv
Nominal Input Power Level 110 dBmV
Ranging Backoff (Start 0, End 4)
Ranging Insection Interval (200 ms)
Tx Backoff Start 2, Tx Backoff End 8
Modulation Profile Group 1
Concatenation is enabled
part_id=0x3137, rev_id=0x3
Range Load Reg Size=0x58
Request Load Reg Size=0xE
Minislot Size in number of Timebase Ticks is = 8
Minislot Size in Symbols = 64
Bandwidth Requests = 0x0
Piggyback Requests = 0x0
Invalid BW Requests = 0x0
Minislots Requested = 0x0
Minislots Granted = 0x0
Minislots Size in Bytes = 32, Map Advance (Dynamic): 2455 usecs
UCD Count = 0
Slots 0, NoUWCollNoEnergy 0, FECCorHCS 0, HCS 0
Req 928887886, ReqColl 0, ReqNoise 0, ReqNoEnergy 928887886
ReqData 0, ReqDataColl 0, ReqDataNoise 0, ReqDataNoEnergy 0
Rng 0, RngColl 113265944, RngNoise 0
FECBlks 0, UnCorFECBlks 0, CorFECBlks 0
MOT#

MOT#show interfaces
ethernet 0/0 is up, line protocol is up
Hardware address is 00:30:b8:80:f0:4f
Internet address is 192.168.1.3/24
MTU 1500 bytes, BW 100000 Kbits
Encapsulation Arpa
(Auto) Full-duplex, (Auto) 100Mb/s, 100BaseTX
ARP Timeout 01:00:00
Last input 00:00:45, output 00:10:50
Last clearing of "show interface" counters never
Last state change at 00:00:25, 2 interface resets
Queueing strategy: FIFO
Output queue 0/100, 0 drops; input queue 0/0, 0 drops
4585 packets input, 296333 bytes
Received 1614 broadcasts, 1605 multicasts
0 input errors, 0 CRC, 0 overruns
0 runts, 0 giants, 0 alignments
1333 packets output, 105973 bytes
0 output errors, 0 collisions, 0 underruns
0 late collisions, 0 deferred, 0 lost carrier

Cable 0/0 is up, line protocol is up
Hardware is Cable, Mac address is 00:30:b8:80:f0:4e
Internet address is 10.15.0.1/16
snmpIndex=2
MTU 1500 bytes
Last clearing of "show interface" counters 1d1h
0 packets input, 0 bytes
Received 0 broadcasts+multicasts
0 input errors,
0 packets output, 0 bytes
0 output errors
Length of output packet queue 0
downstream port 0, snmpIndex=3
upstream port 0, snmpIndex=4
upstream port 1, snmpIndex=5
upstream port 2, snmpIndex=6
upstream port 3, snmpIndex=7
MOT#sho running-config interface cable 0/0

interface cable 0/0
ip address 10.15.0.1 255.255.0.0
ip address 10.10.0.1 255.255.0.0 secondary
ip helper-address 10.0.1.2
cable helper-address 10.0.1.2 cable-modem
cable helper-address 10.0.1.2 host
no shutdown
no ip mask-reply
no ip unreachables
cable downstream 0 frequency 450000000
cable downstream 0 power-level 480
cable downstream 0 rate-limit
no cable downstream 0 shutdown
cable upstream 0 frequency 55700000
cable upstream 0 channel-width 200000
cable upstream 0 power-level 110
cable upstream 0 pre-equalization
cable upstream 0 rate-limit
no cable upstream 0 shutdown
cable upstream 1 frequency 40000000
cable upstream 1 channel-width 200000
cable upstream 1 power-level -160
no cable upstream 1 shutdown
cable upstream 2 frequency 56000000
cable upstream 2 channel-width 1600000
cable upstream 2 power-level 110
cable upstream 2 pre-equalization
cable upstream 2 rate-limit
no cable upstream 2 shutdown
cable upstream 3 frequency 52300000
cable upstream 3 channel-width 1600000
cable upstream 3 power-level 110
cable upstream 3 pre-equalization
cable upstream 3 rate-limit
no cable upstream 3 shutdown
cable dynamic-service authorization-mode unauthorize
ip dhcp relay information option
cable flap-list trap-enable
cable downstream schedule priority-wfq
no cable wireless downstream modulation qpsk

MOT#

With the same configuration that i had those same modems used to connect but i dont know what is the problem now they are not connecting anymore.

We use EuroDocsis modems.

thanks for your help

wittmann
Hmm, next step i would check

Hmm, next step i would check the spectrum of the downstream, if there is realy on 8MHz bandwith. Did you have any QAM-Measurement tool which can locked on the downstream for measuring MER and BER?

There sometimes issues that the CMTS is showing other values as in real.

regards,

wittmann

frosti
Before 2 days couple of my

Before 2 days couple of my friends came to my office to measure the downstream signal it' was everything ok as he measured it.

Well it's kind of strange with this CMTS beucase we dont know yet is it a hardware problem with it or software or do we need to configure something in cmts because with same start-up configuration file worked perfect.

if u dont mind i , can setup a public ip on interface ethernet so u can connect directly and check yourself what is proble.

for passwords just give me your email and illl send it right away.

thnx for your help wittmann

Frosti,

wittmann
Wait a minute, i check the

Wait a minute, i check the config. Is the input power level on the CMTS realy so high?

I saw never before so high input power level. In dB(mV) the input power level is just around 0dB(mV). Your config is showing 110dB(mV). This is definitely to high and the cable modem will no reach the CMTS. i think the configuration is in steps in tenth for upstream but the show controllers show realy 110dB(mV).

Question: Is the config for upstream power level realy in step of tenth?

what shows the questionmark on this command?

cable upstream 0 power-level <?>

Test this:

interface cable 0/0
cable upstream 0 power-level 0
cable upstream 1 power-level 0
cable upstream 2 power-level 0
cable upstream 3 power-level 0

regards,

wittmann

frosti
Dear wittmann I did

Dear wittmann

I did everything as you said but still modem isnt getting connected.
below u will se logs that i have changed the power-level.

MOT(config-if)#cable upstream 0 power-level ?
default Specify default power level
power range channel width Specify power level (in tenth of dB)
<-160,+140> 200 kHz
<-130,+170> 400 kHz
<-100,+200> 800 kHz
<-70,+230> 1600 kHz
<-40,+260> 3200 kHz

MOT(config-if)#cable upstream 0 power-level

MOT(config-if)#show running-config interface cable 0/0
interface cable 0/0
ip address 10.15.0.1 255.255.0.0
ip address 10.10.0.1 255.255.0.0 secondary
ip helper-address 10.0.1.2
cable helper-address 10.0.1.2 cable-modem
cable helper-address 10.0.1.2 host
no shutdown
no ip mask-reply
no ip unreachables
cable downstream 0 frequency 450000000
cable downstream 0 power-level 480
cable downstream 0 rate-limit
no cable downstream 0 shutdown
cable upstream 0 frequency 55700000
cable upstream 0 channel-width 200000
cable upstream 0 pre-equalization
cable upstream 0 rate-limit
no cable upstream 0 shutdown
cable upstream 1 frequency 40000000
cable upstream 1 channel-width 200000
no cable upstream 1 shutdown
cable upstream 2 frequency 56000000
cable upstream 2 channel-width 1600000
cable upstream 2 pre-equalization
cable upstream 2 rate-limit
no cable upstream 2 shutdown
cable upstream 3 frequency 52300000
cable upstream 3 channel-width 1600000
cable upstream 3 pre-equalization
cable upstream 3 rate-limit
no cable upstream 3 shutdown
cable dynamic-service authorization-mode unauthorize
ip dhcp relay information option
cable flap-list trap-enable
cable downstream schedule priority-wfq
no cable wireless downstream modulation qpsk

MOT(config-if)#

thanks for your help and support,

regards,
Frosti

wittmann
Hmm.. Ok, maybe you should

Hmm..

Ok, maybe you should trying 64QAM for downstream.

after the configuration on 64QAM restart the interface cable 0/0 (shutdown / no shutdown).

ok, have you an diagnostig cable modem?

regards,

wittmann

frosti
I did what you said but

I did what you said but still same problem

MOT(config-if)#cable downstream 0 modulation 64
MOT(config)#interface cable 0/0
MOT(config-if)#shutdown
MOT(config-if)#no shutdown

at logs in the modem still get those errors.

3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
3-Critical T002.0 SYNC Timing Synchronization failure - Failed to acquire FEC framing
3-Critical T001.0 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing

what do u think ?

Regards,
Frost

wittmann
If the receive power level

If the receive power level on the cable modem is still around +16dB(mV) trying to set the power-level on the cmts lower or use an attenuator.

the logs from the cable modem says to me there is somethin wrong with the downstream signal. Before the cable modem can use the MPEG TS the FEC is failed. This was the reason for my question of the signal quality of the downstream. You can measure a good power level but this will not guarantee a good quality.

regards,

wittmann

frosti
Dear wittmann, We are

Dear wittmann,

We are looking to do those things are you said and find attenuator we repaly to you soon as we try those tests,

thanks for your help and support.

Frost

frosti
Does anyone can tell me is

Does anyone can tell me is this HARDWARE problem or Software problem , what do we need to to to make this cmts working.

Any idea would help a lot

Frosti

wittmann
If there no strange hidden

If there no strange hidden commands on the config which i can't see, the combing and splitting network is right and you will not see any reactions of cable modem on the cmts, like init(rc) aso. i would say the hardware has a problem. But without any measurements by myself i will not give any guaranty. ;-)

regards,

wittmann

mtntrailseeker
CMTS PROBLEM / Modems not connecting

Do you have a diplex filter in the combining system? Is it hooked up correctly with the downstream and upstream connected to the correct legs?

cmcaldas
back to basics

You didn't mention how far the modems got. did they range ok, but not get an ip? if you do a show cable modem and see how far the modem gets, example dhcp(d)? I believe it's a simple route problem. from the dhcp server, can you ping the modem gateway?
can 10.0.2.1 ping 10.15.0.1? you may need to add a route that the 10.15 class B network you setup is behind the fast enet port. it's not a bridge, btw, what ver sw is it running?

~Carl

frosti
downstream is not working

downstream is not working it's hardware problem , we returned back to our dealer where we bought it for repair downstream is broken it's not working.

thank all of you for your help and support shearing your ideas to help me .

Regards,
Frost

wittmann
did you use the right/same

did you use the right/same annex [a|b] type as the cable modem?

I see no downstream configuration, so I think it should be default annex b (6MHz DS freq bw). Did you use DOCSIS or EuroDOCSIS?

have you more informations about the interfaces? (show interface ...)

regards,

wittmann

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