[zeromq-dev] ZMQ_RATE

[Emmanuel TAUREL]

Hello all,

I am experimenting PUB/SUB sockets with PGM protocol.
I am actually using with the ZMQ_RATE socket option.
My understanding of this parameter was that it is the maximum rate for 
sending/receiving data and thus limits the network bandwidth used by PGM.
In my test, the publisher sends messages as fast as it can.
I have tried different value for the ZMQ_RATE parameter: 100 which means 
100 kbits/sec (the default) and 80000 which means 80Mbit/sec.
I capture network packets using wireshark. When I look at its IO graph 
after the capture, there is no difference between the two runs.
During the PGM transmission, I always have a network usage close to 100 
Mbit/sec which is my network bandwidth between the pub and sub hosts.

Where is my error?
Do I have to understand that ZMQ_RATE limits the data rate in the 
process but not on the network (meaning buffering required in case of 
slow ZMQ_RATE)?

Thank's for your answers

Emmanuel Taurel