When a header contains contact information, it is typically added using the 'SIP URI' format:

• A SIP URI is like an email address. In its simplest form, it appear as sip:content@hostname.

• The SIP URI can also indicate the target port: sip:content@hostname:port

• For some headers, the SIP URI can also include preferred display name. When that happens, the sip: part is enclosed in < > brackets. For example: display <sip:content@hostname>.

  • From the caller name, the line's Name Priority setting sets whether this name is displayed on internal phones or replaced by a name match from the system or user directories.

• Some line providers may use a different format called TEL URI. That takes the form tel:123456789.

• The system can use SIPS format which replaces sip: with sips:. This is used to indicate that the connection should use TLS from end to end. That is, every hop should use TLS.

The header format used by each SIP line in the system configuration is set by its URI Type setting. See Selecting the SIP Header Format Used.