Re: Deschall Offline Processing

Rocke Verser (rcv@dopey.verser.frii.com)
Wed, 9 Apr 1997 18:13:25 -0600


In an effort to be fault tolerant, and borrowing from the protocol
used by the European RC5 client, the DESCHALL clients send a
request via UDP to the server. If no response is received after
a specified timeout, they try again.

The timeout starts out at 10 seconds. Each timeout increases the
next timeout by 10 seconds until it reaches a maximum of 10 minutes.

This actually seems to work pretty well. If you have a method of
autoconnecting on packet activity, the delay is rarely more than
20-30 seconds. If you have waited a long time to reconnect, the
delay will still be a small percentage of the time you waited.

At the server's end, assymmetric routes and pesky firewalls sometimes
cause a packet to arrive at the server, but the response cannot be
delivered to the client. The server will receive the same packet
over and over from the client, sometimes for hours.

A shorter timeout would needlessly increase the load on the server.