Asterisk: The Future of Telephony, 2nd Edition

SIP

Just as with IAX, the SIP configuration file (sip.conf) contains configuration information for SIP channels. The headings for the channel definitions are formed by a word framed in square brackets ([])—again, with the exception of the [general] section, where we define global SIP parameters. Don’t forget to use comments generously in your sip.conf file. Precede the comment text with a semicolon; everything to the right will be ignored.

General SIP Parameters

The following options are to be used within the [general] section of sip.conf:

allowexternalinvites

If set to no, this setting disables INVITE and REFER messages to non-local domains. See the domain setting.

allowexternalinvites=yes|no

allowguest

If set to no, this disallows guest SIP connections. The default is to allow guest connections. SIP normally requires authentication, but you can accept calls from users who do not support authentication (i.e., do not have a secret field defined). Certain SIP appliances (such as the Cisco Call Manager v4.1) do not support authentication, so they will not be able to connect if you set allowguest=no:

allowguest=no|yes

allowoverlap

If set to no, overlap dialing is disabled:

allowoverlap=no|yes

allowsubscribe

Specifies whether or not to allow external devices to subscribe to extension status (as set in the hint priority). Defaults to yes:

allowsubscribe=yes|no

allowtransfers

If set to no, transfers are disabled for all SIP calls, unless specifically enabled on a per-user or per-peer basis:

allowtransfers=no|yes ...