LCP traffic vs ping - PPP

This is a discussion on LCP traffic vs ping - PPP ; Hi all, So pppd can detect our embedded system is in a place without GPRS network, we use theses options : lcp-echo-interval 30 lcp-echo-failure 5 It seems to work fine here : without the antenna, pings are lost, lcp echo ...

+ Reply to Thread
Results 1 to 3 of 3

Thread: LCP traffic vs ping

  1. LCP traffic vs ping


    Hi all,

    So pppd can detect our embedded system is in a place without GPRS
    network, we use theses options :

    lcp-echo-interval 30
    lcp-echo-failure 5

    It seems to work fine here : without the antenna, pings are lost, lcp
    echo request stay without answer and after 5 failures pppd retry a new
    connection.

    But our client tells us that sometimes all pings are lost while echo
    request-response are ok.
    Is it possible ?

    --
    Manu



  2. Re: LCP traffic vs ping

    "Manu" writes:
    > But our client tells us that sometimes all pings are lost while echo
    > request-response are ok.
    > Is it possible ?


    Sure. It means that the low-level PPP session is still active (the
    peer PPP implementation is still responding), but the IP layer portion
    is broken.

    This could be due to:

    - Routing problems; the system that you're pinging is 'behind'
    (routed a hop or more away) the peer, and the route to that
    host or back towards the peer is broken.

    - Any of a number of bugs. E.g., the local system has removed
    the interface route for the PPP link from its local IP
    tables (for whatever reason). Or the remote has done this.
    Or the peer's IP stack has crashed but the PPP link itself
    is ok (possible on some modular implementations).

    You'll need to do a lot of debugging to find out what's going on here.
    The fact that GPRS is part of the system makes things quite a bit more
    complex, as the way GPRS interconnects the host, phone, and access
    devices is subtle and complex.

    --
    James Carlson, IP Systems Group
    Sun Microsystems / 1 Network Drive 71.234W Vox +1 781 442 2084
    MS UBUR02-212 / Burlington MA 01803-2757 42.497N Fax +1 781 442 1677

  3. Re: LCP traffic vs ping

    James Carlson wrote:
    >> But our client tells us that sometimes all pings are lost while echo
    >> request-response are ok.
    >> Is it possible ?

    >
    > Sure. It means that the low-level PPP session is still active (the
    > peer PPP implementation is still responding), but the IP layer portion
    > is broken.


    Lot of Thanks !

    --
    Manu



+ Reply to Thread