MA5800-X7 + MA5633- Cable Modem connectivity issues with CM model Arris Touchstone TM822S
Issue Description
There is a PoC/Test with customer for their Cable Network using Huawei DCCAP solution (MA5800-x7 as GPON OLT and MA5633 D3.1 + D3.0 ready as Optical Node/D-CMTS).
A basic network setting has been installed so the client could test our Cable/DOCSIS products and interoperability with their system (DOCSIS provisioning systems and LIVE network cable modem models).
Their services (High-speed Internet / DVB-C broadcast TV / SIP based VoIP services) were tested and are running fine under MA5633 D-CMTS just for one of their Cable Modem models (“ARRIS Touchstone TG2492S-85”), while DOCSIS services / connectivity is faulty (cable modem status goes offline right after “online” state) for the older CM version “ARRIS Touchstone TM822S”.
Handling Process
Asked to collect logs ont MA5800-X7 as below:
huawei>enable huawei#config huawei(config)#undo smart huawei(config)#scroll huawei(config)#display patch all huawei(config)#display board 0 huawei(config)#display board 1 huawei(config)#display current-configuration huawei(config)#display cable modem phy huawei(config)#display cable rf-power [frameid] upstream huawei(config)#display cable rf-power [frameid] downstream huawei(config)#diagnose huawei(diagnose)%%display reset-record huawei(diagnose)%%display cable modem status trace [cm-index] // all the CM huawei(diagnose)%%display cable modem departure-reason [cm-index] // all the CM huawei(diagnose)%%display cable modem cfg-file [cm-index] // all the CM, for offline CMs, please collect when cm get online huawei(diagnose)%%debugging cable modem [abnormal cm MAC] mac-mgnt-msg all tlv // wait CM get online 2 times, then input the command bellow. huawei(diagnose)%%undo debugging cable modem [abnormal cm MAC]
these command bellow, please input one bye one, don’t copy and paste them all.
huawei(diagnose)%%transparent on 2/0 huawei(diagnose)%%debugging bcm3219 linux print on 255 huawei(diagnose)%%debugging bcm3219 linux huawei(diagnose)%%macmgr cmtrace show mac [abnormal cm MAC] huawei(diagnose)%%macmgr cmtrace show mac [normal cm MAC] huawei(diagnose)%%transparent off huawei(diagnose)%%display cable event history detail huawei(diagnose)%%display alarm history all list huawei(diagnose)%%display event history all list
Root Cause
After receiving the logs ( attached) we can conclude that:
<1>
The departure-reason the this CM
We can find the departure-reason(offline-reason) of this CM is BAD_RCC_TCC.
This reason is send by CM(in Reg-Msg)
<2>
The departure-reason(offline-reason) carried by CM
<3>
Possible reasons for this issue
This reason is send by CM, we can’t judge the reason accurately, because it is related to the requirement of CM.
But we can give possible reason of this issue by our experience.
We have confirmed the CM 4 bound downstream channel 1-8.
We have checked the configuration and find there are two possible reason maybe lead to this issue
Point 1: There are gap(16M) between channel 4 and channel 5, some CMs don’t support this big gap.
Point 2: The frequency of some channel is too low, some CMs maybe can’t support so low frequency.
Solution
Disable the downstream channel 1-4, only keep downstream channel 5-12, and check cm 4 could get online or not.
After this action, the CM went online.