Mitel 6800 Series, Administrator'S Manual, Page: 628 / 1113

Mitel 6800 Series SIP Phone Release 4.2.0 SP2 Administrator Guide
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CONFIGURABLE “ALLOW” AND “ALLOW-EVENT” OPTIONAL
HEADERS
On the IP Phones, an Administrator can enable or disable whether or not the optional “Allow”
and “Allow-Events” headers are included in the NOTIFY message from the phone.
SIP NOTIFY messages from the phone may contain optional headers called “Allow” and
“Allow-events”. If the NOTIFY message contains these headers, the UDP packet returned by
the server may be too large and may fragment the packet. To prevent the fragmenting of the
UDP packet, the “Allow” and “Allow-events” headers may be removed using the parameter,
“
sip notify opt headers
”. If this parameter is set to “
0
” (disabled), the optional headers are not
included in the SIP NOTIFY message which reduces the size of the packet returned by the
server, and prevents fragmentation of the packet.
The value set for this parameter specifies whether or not to include the optional headers in the
SIP NOTIFY message from the phone.
An Administrator can enable/disable the optional “Allow” and “Allow-Event” headers using the
following parameter in the configuration files:
• sip notify opt headers
ENABLING/DISABLING OPTIONAL “ALLOW” AND “ALLOW-EVENT”
HEADERS
Use the following procedure to enable/disable “Allow” and “Allow-Event” headers.
For the specific parameter you can set in the configuration files, see Appendix A, the section,
“Optional “Allow” and “Allow-Event” Headers” on
page A-294
.
CONFIGURABLE SIP P-ASSERTED IDENTITY (PAI)
The IP Phones support a private extension to SIP for Asserted Identity within trusted networks
(as defined in RFC 3325). This feature allows a network of trusted SIP servers to assert the
identity of authenticated users, and verify that phone messages originate from a Trusted Identity.
Upon receiving a message from a caller in the Trusted Network, the IP phone reads the contents
of the P-Asserted-Identity (PAI) header field and displays it on the phone UI. This field contains
a more accurate description of the caller identity (extension/phone number) than is contained
in the SIP message.
When an IP phone receives an incoming call, the IP phone performs the following actions:
CONFIGURATION FILES
Notes:
1.
The phones support PAI header in the UPDATE message, according to
draft-ietf-sipping-update-pai-00. This feature is always enabled.
2.
If an UPDATE is received with a PAI header from a trusted source, the phone updates
the display with this information. The phone ignores any PAI received from untrusted
entities.