DEFINITY ECS Release 8.2 Maintenance for R8.2csi
555-233-119 Issue 1
April 2000
Maintenance for csi systems
1-97Multimedia Call Handling
1
4. Find another available port, then:
a. Busyout the port to which the end point was connected .
b. Make another call to the same c onference. If the problem correc ts
itself, then the previous port may b e bad. If there are other VC
boards with sufficient availab le ports to replace c alls on the current
VC, then pull the board that has the b ad endpoint on it (the status
conference command disp lays the encoder p ort associated with
the call). The system will automatically reestablish the VC
connections without drop ping the call. If th is fixes the problem, then
replace the board, as it has at least one bad port. Reseating the
board may temporarily fix the p roblem due to the hard reset done to
the board.
Audio Echo
Echo in conference calls, particularly those with large delay characteristics, is
totally disruptive. When Voice Activated Switc hing is taken into account, the
effects are disastrous. Various arrangements of the microp hone(s) and room
speaker(s) may be needed.
For some Lucent Technologies Vistium endpoints, if an external sp eaker is
attached or was attached when the system was last rebooted, this end point will
cause audio echo throug hout the conference. First, isolate the offending
endpoint by asking each endpoint to mute, one at a time, until the echo
disappears.
If the input from an endpoint is loc ated too close to the sp eakers of an endpoint,
then acoustic echo is c reated. The microphone must be mov ed away from the
speakers.
Normally, if any microphone in the room is moved relative to the speakers, that
site will cause echo until the ech o canceller in the codec retrains itself, some will
require a manual reset. If a PictureTel keypad is configured with external
microphones connec ted to the keypad, then the inte rnal microphone and
external microphone(s) “s ing” to each other if the “ ext mic” bat switc h is set to
“int mic” on the b ack of the keypad. In this c onfiguration, VAS locked on that site,
and the acoustic “ singing” was inaud ible.
Rate Adaptation
Because of a lack of a cl ear explanation in standards, someti mes endpoints do
not work well with each other and the DEFINITY MMCH. The MMCH will only
allow a conference to downg rade from 64kbps to 56 kb ps operation on
conferences that have the Rate Adaptation flag s et to y.
When a downgrade does oc cur, information on the Status Conference form
indicates the succ ess or failure of the 64kbps-endp oints that are particip ants to
properly rate adap t to 56kbps. As a general ind ication that the conference ha s
rate adapted, the Conference Transfer Rate and Effective Transfer