Asterisk load test

Hi.I use sipp tool for asterisk load test.
When using 100 concurrent calls everything it is ok. (./sipp -sn uac -d 100000 -s ext asterisk_ip -l 100 -rtp_echo)
But when i increase concurrent calls to 300 (./sipp -sn uac -d 100000 -s ext asterisk_ip -l 300 -rtp_echo) get retransmission errors (Retransmission timeout reached on transmission).

There will always be a point where things will fall apart. As well with chan_sip it’s single threaded for UDP traffic, so there can come a point where it just can’t keep up.

What exactly are you trying to accomplish or seeking help with?

i want load test asterisk (with concurrent call count 300)

That’s what you’re doing. Do you instead want Asterisk to handle 300 calls fine? If so you 'd need to identify the bottleneck and figure out what is going on.