4 troubleshooting cases of EPON/GPON equipment

 In previous posts, our blog try to introduce trouble shooting basic idea, and here share again with detail actual FAQ case.

 Regarding the terminal problem, FOT NMS (network management system) provide a way for our customers remotely collect debugging, tracing and related information, then output to specified PC, and save as Log file for further analysis.

As we know, FTTH PON equipments have been in used for certain time today, and there are more or less some faults , which is headache.The following four common PON equipment faults case was chosen as the examples for our troubleshooting case.Hopefully our readers can learn some basic PON equipment troubleshooting idea, that we can solve PON device’s problem more efficiently.

Case 1: Network Management System disconnected

 NMS system’s disconnection problem is quite frequency, let’s start with idea to debug and troubleshoot this No.1 PON equipment faults issue. what we need to do is just check the list step by step as following,  if we found our OLT/ONU disconnected to the NMS system unluckily .

  1. Check cable status.
  2. Check the IP address setting.
  3. Check the subnet number and network settings.
  4. In-band and out of band management IP cannot be set on the same IP address.
  5. Restart OLT after modifying the subnet or network number.
  6. Check NMS VLAN configuration, if in-band NMS disconnected.
Equipment NMS system(example)

Equipment NMS system(example)

Case 2: Fail to detect ONU/ONT

 Another headache problem is failed to detect their ONU/ONT users.  Idea to solve this kinds of problem, could be refer to those steps.

the problem”failed to detect their ONU/ONT users” is usually occured at monitoring C.O (center office).
  1. Input command: display running-configuration
  2. Check ONU type
  3. Check if any abnormal event logs and alarm. 
  4. Connect ONU with PON port in OLT directly, check whether can detect ONU (Note: Be careful the over-high optical power when ONU connect with PON port directly)
  5. Connect to another PON line card or PON port and check whether can detect the ONU
  6. Replace with another authenticated ONU to check whether it’s ONU problem
  7. Check ODN, whether there is problem in optical network.

Case 3: Fail to access internet

 “Fail to connect” is another big big issue for our end users, no worries, we can follow those steps one by one to fix it.

  1. Check ONU register status in ONU management interface.
  2. If register is ok, check the VLAN configuration in OLT and ONU.
  3. Check whether bandwidth setting is too small.
  4. Configure spare Ethernet port in switch line card in untag mode and add to VLAN, modify PVID value to the corresponding VLAN number, then connect a PC with ONU and test network access.
  5. If fail to access internet, the problem maybe in uplink network. Check the uplink port status and uplink switch VLAN configuration.
  6. If network is ok, then the uplink network is ok. Connect only 1 pc ONU with PON port, after registering, set the ONU VLAN number and test internet access.
  7. If it’s ok to connect 1pc ONU, then connect other ONUs one by one and see whether there is problem when connect an ONU.
  8. If the ONU connect to LAN or several cables, in order to eliminate the LAN problem, disconnect them and connect to only 1 PC to do test.
    ONU-OLT protocol analytics flow(part)

    ONU-OLT protocol analytics flow(part)

Case 4: VoIP function problem

 For those CPE equipment which support the Voice/VoIP function, it is also a very headache problem of call issue. We have to fix it as soon as possible if the analog/sip phone fault to call.

  1. If the link between VoIP FXS port/chipset and SIP Server/IP PBX is ok.
  2. Whether can ping VoIP IP address via SIP server, if it is failed then got to check port configuration on VoIP card on EPON and related connection status.
  3. For static IP access, please check IP address and Port ID on the service card on EPON;
  4. For DHCP/Domain access, please check if the configuration on terminal and server side match or not.
  5. Luckily ONU/ONT terminal successfully register, but fail to make a call, what we need to check is the USER TID and RTP TID configuration between client and sip server.
  6. Imaging all the configuration mentioned above is correct, the best way to debug is using the protocol flow analytics via sip sever.

 And this related post hope a bit useful for you.Thank you for reading:

FTTx triple-play service config series posts (Index)

6 steps to config GPON’s triple play service

  1. No wonder optical networks are in such a poor state, especially if people like FOT are managing them. The language and grammar on this site is so bad you probably can’t read the instruction manuals for optical network equipment. I guess you are trying to drive customers away. 100% success with me, I will never visit your site again or recommend you to anyone.

  2. hi i m facing one problem in cisco m4600 i m a ISP in amanora park city in pune
    there is another YOU broadband ISP and we both have VLAN base conectivity ..but at customer end onu it changes the Vlan frequently ..evry minut..what is the issu?

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