WCF REST service know when client terminates -

WCF REST service know when client terminates -

i developing network card game

my server wcf not restful because saving cookie client id identify client each request.

from moment know client other info retrieved database (cards has in hand example)

there utilize case player connected room , kill client process (not exit nicely telling server left room)

how can notified in server user not connected room anymore (and user ter

wcf rest client-server server