Session Initiation Protocol

In 2020, as previously mentioned SIP is replacing most of the desktop phones. SIP stands for Session Initiation Protocol.  H323 or SIP is neither better or worse of standards, it only differs how the phones connect and disconnect calls. Cisco’s SCCP uses H323 standard, even though the protocol itself is proprietary. Your routers IP address handles the configuration (buttons and lines, sometimes for the user like backdrops and ring tones), the time clock (the time of day and day of the year), the signaling (the tones), and the transmission (the human conversation). SIP could do any of the four things and could be separate devices on separate networks.

The basis of the SIP “stack”/protocol/extension supports

• Video chats
• Audio calls (err the traditional telephony)
• Instant Messaging (known as “texting”, “messaging” or “chat” if someone has been born after 1994
• The basic SIP telephony stack supports essentially all standard 19 Custom Calling Features that the phone company used to provide separately, that many broadband phone companies provide for free or is included at a much lower price rate.
• The protocol literally revolves around Caller ID. “Display Name” and “SIP Alias” is equivalent to the “station-id name” and “station-id number” in the FXO ports respectively  in the IOS configuration if you wanted to do ethical caller ID spoofing.)

Continue reading “How to Implement Cisco Call Manager Express at Home, part five”