CocoaAsyncSocket supports TCP and UDP. The AsyncSocket class is for TCP, and the AsyncUdpSocket class is for UDP. AsyncSocket is a TCP/IP socket networking library that wraps CFSocket and CFStream. It offers asynchronous operation, and a native Cocoa class complete with delegate support or use the GCD variant GCDAsyncSocket. AsyncUdpSocket is a UDP/IP socket networking library that wraps CFSocket. It works almost exactly like the TCP version, but is designed specifically for UDP. This includes queued non-blocking send/receive operations, full delegate support, run-loop based, self-contained class, and support for IPv4 and IPv6.
Opus is a totally open, royalty-free, highly versatile audio codec. Opus is unmatched for interactive speech and music transmission over the Internet, but is also intended for storage and streaming applications. It is standardized by the Internet Engineering Task Force (IETF) as RFC 6716 which incorporated technology from Skype's SILK codec and Xiph.Org's CELT codec.