Supporting more 50 webrtc::PeerConnectionInterface s

How to create more 50-100 webrtc::PeerConnectionInterface object in mobile devices ?

What steps will reproduce the problem?
1. create 30-40 webrtc::PeerConnectionInterface s with PeerConnectionFactory
2. start connect each peer connection with remote side
3. wait offer in signaling thread.

What is the expected result?
Offer should be created each time, and success connected all peer connections with remote side.

What do you see instead?
Offer can’t create after 20-30 peer connections are created , webrtc signaling thread can’t answer any queries. Some times in Android crashes or freezes the process.

What version of the product are you using? On what operating system?
Android, and iOS

on Linux all are OK, able to create more 500 peer connections.

Please provide any additional information below.
(1) webrtc branch head 4896

(2) some times increasing RLIMIT_NOFILE to 64000 helps to create a little more peer connections.