> > Too bad. I don't know the DTLS protocol, but isn't it possible to do the > server > part with a single UDP socket? If you keep track of the already connected > clients, you know if the just incoming packet is a connected or connecting > client, > and then you can use different threads to handle the packet further. > > > Corinna >
Corinna, I suppose that it would be possible with a different API. The API that OpenSSL provides makes it rather difficult. A DTLS session is "served" by a BIO object that has a dedicated socket underneath it. I am not aware whether a workaround is possible. May be application can replace that BIO with something "artificial" but I am not sure that that's possible. The same problem happens even with "plain" UDP when many clients (thousands) are talking to the same single UDP port (for example, a TURN server). The workaround would be to create an extra application layer on top of sockets layer to differentiate packet "streams" by their remote address. With POSIX behavior, such a layer is not necessary. Oleg
