I noticed a really interesting problem when using Kannel hooked up to an operator using an SMPP3.4 server.
When the send_enquire_link interval was set to 5 seconds, I noticed in the kannel logs that it did indeed send the keepalive. However, only the first keepalive request received a response. Each additional keepalive didn't garnish a response and then after a couple more tries, it would disconnect + reconnect. Messages sent out via kannel to handsets via the SMSC kannel was connected to would get to the handset ONLY if they were sent BEFORE any of the keepalive requests had been sent..i.e. just after the system connected. As long as I kept the system busy, it wouldn't send keepalive requests, and I could keep sending messages. So I disabled the keepalive to ensure we could always send messages. First off, has anyone encountered this with any smsc's they've worked with? Any work arounds that are better than disabling the keepalives because I think they may be causing a problem I'm having below. I'm going to find out what brand of SMSC we're dealing with in this case to compare. PROBLEM 2: Now that I've disabled the keepalive, the sends seem to work perfectly. However, at some point, the connection between kannel + the smsc seems to get disrupted...possibly on the receive channel only. The net result is that I can still send messages out just fine, but incomming messages stop. If I stop and start kannel, the smsc on the other end will have queued up the failed messages and pass them through. Looking at hte logs, there is no indication that the connection was severed...AND we're still able to send outgoing messages. Would the keepalive test find + resolve this issue (by reconnecting)? Or is the keep alive ONLY for the transmitter bind? If so, is there a way to turn it on for the receiver bind? OR...is there something simple I'm forgetting here? Or has anyone else seen/solved this problem? Help is much appreciated! Bryce
