Nortel DMS-250 Reference Manual page 65

Table 4-2
Q.931 message information elements
Q.931
message
Information element
Display
Information request
Calling party number
Redirecting number
PROG Protocol discriminator
Call reference
Message type
(continued)
Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
Message structure and function 4-17
Direction Type
Both Optional. Included in the
user-network direction if the user
has display information that should
be passed to the far-end user. It is
included in the network-user
direction if received from the
remote user. As a network option,
the display information element can
be passed from user to user
without network interpretation or
interaction.
Both Optional. The network can provide,
on a subscription basis, the ability
to transfer the information element
between users without network
interpretation or interaction.
Both Optional. Mandatory in the
user-to-network direction if the
calling party number to be used is
not the default number for the
interface. In the network-to-user
direction, this information is made
available to the called user upon
subscription to the corresponding
ISDN supplementary service.
Both Optional. The network can provide,
on a subscription basis, the ability
to transfer the information element
between users without network
interpretation or interaction.
Both Mandatory
Both Mandatory
Both Mandatory
—continued—