Understanding ports 5060 and 5061 that are associated to the Session Initiation Protocol (SIP).
10:22 08 June 2017
Port 5050 is assigned to clear text SIP while port 5061 is assigned to encrypted SIP, also known as SIP-TLS or SIP over Transport Layer Security encrypted channel.
SIP or Session Initiation Protocol is used for Internet multimedia conferencing and communications (such as VoIP). It focuses on the management and negotiation of all the features of VoIP sessions such as setting up and tearing down VoIP calls.
SIP is a text-based request and response protocol that allows multiple request methods. Its messages are ASCII encoded and use standard Multipurpose Internet Mail Extensions (MIME) capabilities, which are integrated with Real-time Transport Protocol. SIP negotiates the ports used for RTP communications when a new VoIP or multimedia session is established. However, some providers do not use SIP over standard ports, which breaks down communication between providers. These may mean users ending up opening the ports in more firewalls and SOHO environments in order to use the service.