Nortel Networks NN43001-321 User Manual

Page 16

Converged Desktop Services

When a call terminates to the CS 1000 telephone, the CDMV or CDMO
Class of Service redirects the call to the CSDN defined on the telephone,
before ringing the CS 1000 telephone. The CSDN is a CDN used for CDS.
This CDN number is also configured on the Signaling Server so that it can
be acquired by the CDS application when the Signaling Server starts.

When the call terminates to the CDN a message is sent over AML/VAS to
the CDS as notification of the incoming call. If the call is a virtual trunk
call, and queued on a CDN, a Digital Signal Processor (DSP) resource is
used to play the ringback to the caller because CDN is a TDM resource. (A
DSP resource is required to handle media between a TDM resource and
an IP resource.) The CDS cannot determine where the call terminates,
either on the CS 1000 telephone or in the SIP network; the termination
location is based on the user’s Advanced Screening options in the MCS
5100 Client. Therefore, the CDS instructs the Call Server to make a Virtual
Trunk call to a predetermined number, as defined on the Signaling Server
(the Service DN used for making a VTRK call from an Agent) and the CS
1000 dialing plan. This call reserves a Virtual Trunk in case it is required to
terminate the call to a SIP device (if so configured in the user’s Advanced
Screening options). After the Virtual Trunk call is established, CDS sends a
SIP INVITE message to the MCS 5100 using the SIP Gateway Application.

The MCS 5100 receives the INVITE message and processes it on the
user’s PC Client. The user’s Advanced Screening options are checked for
any rules that determine the destination. If no rules exist and the user is
in Converged Mode, the MCS 5100 notifies the CDS application to notify
the converged telephone. The CDS bridges the call and the Virtual Trunk is
dropped. An MCS 5100 call notification screen-pop appears, and the CS
1000 telephone rings. The call is answered on the CS 1000 telephone and
call logs are generated on the MCS 5100 PC Client. If the caller is another
SIP device or Converged Desktop user, all MCS 5100 features become
available for the call.

For outbound calls, the user may use their MCS client in a Click-to-Call
scenario or use the keypad of their CS 1000 telephone. When using the
MCS 5100 Client, the user has access to all directories available and can
process a call. When the user selects a directory entry or dials a telephone
number, the MCS 5100 sends an INVITE message to the CS 1000, and
CDS processes the call to the CS 1000 telephone. The telephone must be
answered before CDS can process the second leg of the call. When the call
is answered at the CS 1000 telephone, the destination called and the two
calls are bridged together. The PCA application is used for making these
calls. The MCS 5100 Client activates call logs. If the destination is another
SIP device, the MCS 5100 Client allows multimedia features.

Nortel Communication Server 1000

Communication Server 1000 to MCS 5100 Converged Desktop Type 2 Configuration Guide

NN43001-321

01.05

Standard

Release 5.0

15 February 2008