Chat closing problem

I have a long running problem with the chat plugin. The other person and myself will stop receiving messages from each other. The only indication something went wrong is we might get a "Chat session to Friend closed" message. However if we get the message, it's not until some time after we stopped receiving each others messages. I end up frequently holding one sided conversations with myself.

This problem seems to occur most often when we're only sending messages intermittently. When there's a frequent flow of data (such as snooping the mud) this chat closing problem tends to occur far less frequently or not at all.

Any ideas on this or solutions would be appreciated.

Sounds like your router's closing the socket after timing out. The most reliable way to fix it is to go in to the webpage on it, and set up port forwarding so that if the connection does time out, your friend's next message will reopen the socket.

The steps to do this differ on each model of router, but the place to start is opening a command prompt (start/run.../cmd) and typing ipconfig. make note of your default gateway and go to that ipaddress in a web browser. Linksys and Belkin routers have online help that you can search for 'port forwarding'. If given the choice between port forwarding and DMZ mode, DO NOT pick DMZ for your computer since that basically negates any protection the router's firewall gives you.

Yep, my router did this to me. To test this...

Use telnet, sign on a MUD and do not receive or send any data for like 15min. If the connection drops after a while (not caused by the MUD), it's the router.

Do you do a #chatall - or a #chat <who> <message>?

If you do a #chatall, and don't notice the message about the dropped connection, then it is probably happily sending your chats to the reduced number of people in the chat group.

I think if you chat to a specific person, it should tell you if they are not connected.

Unfortunately, for you to get a "chat session closed" message, the client needs to be actively notified that the connection is dropped. However if a router silently discards a connection, this may not happen.

As an analogy, imagine if you were talking to someone on the phone, and they quietly put the phone down and walked away. You wouldn't realize they weren't there until you noticed they weren't replying to you.

The nature of TCP/IP is that if a packet is lost, it retries sending it, and thus it is possible for one end to not be sure if the other end is there, or not, for a minute or so.

What you might be able to do to help here is use a custom message number, in a script, to keep testing if the connection is still open. See near the bottom of this page:

http://www.gammon.com.au/mushclient/chat.htm

For example, each end could send each other a custom message every 5 seconds or so. Now if they don't *receive* a message after 10 seconds, they might assume the connection has been dropped.

Also doing the above will keep the socket alive, so it doesn't time out.

Yes, checking for the problem will cure it, eh? In that case you can set up the timer to send the custom messages, and not bother testing to see if they arrive. :-)

Thank you gentlemen. This is so odd, I'm already using port forwarding for the dedicated chat port. Without an open port my friends have their connection attempt refused and are unable to connect to my chat. Even though their calling me perhaps it's not my router but theirs?


I'm not using #chatall either, using #chat user msg. And you're right, I receive the chat closed message often after attempting to send a message but previous messages still went missed.


Using a script routine to keep the chat alive would be perfect. Would any routine in particular not create visible output spam?

That's also possible, Rich. If the socket times out and closes on their NAT, your machine has no way to re-establish the connection unless they have port forwarding defined as well.

Thanks I'm going to bring that up.