GE865 Ping and packet size

4 thoughts on “GE865 Ping and packet size

  1. Hi All,

    I have a relatively large number of GE865 devices deployed in Ireland and UK. They use roaming SIMs and camp on many different networks. I have ping turned on via ICMP command. I notice that most devices will respond to pings with size=1k but a small number (less than 10%) will not and will only respond if the packet size is about 300B or less. This also applies to UDP packets – problems / blocked over 300B. I have observed no particular pattern yet in terms of networks, but I assume that this must be a configuration somewhere along the path in the network. Presummably at or near the RAN.

    Can anyone confirm this and explain what is going on?

    Part of our application uses UDP packets of about 1K. Obviously the above limitation means that sometimes we have to switch to smaller packet size. The 1K packets are preferrable for us because it improves transfer time for our small files (we use a home made FTP over UDP).

    Thanks folks,

    Ciarán

    1. Hi Ciaran,

      If I understood correctly, you are sending ICMP Echo requests to these modules and some of them doesn’t reply.
      And the modules that doesn’t reply have issue with small UDP packets as well.
      These SIM cards, do all of them belong to the same operator? Do you use a private APN and communicating with the modules from a private network? Or do all of them have a public IP address?

      Do you know the SW version on these modules? Is the same on all of them? The command to check it is AT+CGMR

      1. Hi Taj,

        No, you misinterpreted my explanation. Let me restate the issue more clearly.

        1. Many thousands of devices in the field.

        2. All devices reply to ping with size <= 300B

        3. A small number of devices do NOT reply to ping with sz > 300B (but are ok with sz < 300B)

        4. All devices on private APN

        5. All devices v10.01.000

        6. The ping size behaviour also applies to normal UDP traffic.

        Thanks again,

        Ciarán

        1. Hi Ciaran, I think that you are already in contact with my colleague Luca for another issue that you have.
          We will contact you by email and we will continue a more detailed investigation there.