3 ms·
What we found when working with UDP (multicast) at a previous gig (its been a while). The messages can be up to around 64KB. I say "around" because if differe
by acomjean 10y ago
What we found when working with UDP (multicast) at a previous gig (its been a while).
The messages can be up to around 64KB. I say "around" because if different OS's based on experiment did different things (this caused us much confusion). I think HPUX would drop them silently on send if they got to 62. at 64 it would return an error. Keep them below 60 to be safe.
Multicast means the router has to be set up correctly. When they muck with the network and add a hop, make sure your TTL (time to live) is set correctly on send. One of our OSs had a strange default to this.
I liked the all or nothing receive nature of UDP messages. Never a waiting and reading for the rest of the data like with TCP. You have no idea if the message got to where it was sent, sometimes you don't need that. Very low overhead too.
Multicast was the selling point for us. Send and everyone attached to the group gets the message. You can subscribe to the groups and see all the messages which makes debugging easier.