Cisco Cisco Unified MeetingPlace Audio Server Installation Guide
Cisco MeetingServer 5.1 Installation Planning Guide
53
Cisco Systems
March 2003
Action
Description
9
9
9
9
Signaling
E&M Wink Start, or
E&M Wink Start, DTMF digits, and DID/DDI, or
Loop start only
Coding
Format
B8ZS (preferred), or
Jammed Bit (bit stuffing), or
AMI
13
Framing
Extended super frame (ESF)
14
(preferred), or
Standard super frame D4 (SF/D4)
Additional
Hardware
Channel service unit (CSU) required for each digital T1
connection over 100 meters (330 feet) from demark; or
from PSTN
connection over 100 meters (330 feet) from demark; or
from PSTN
8.
Modem
Requirements
Requirements
Analog telephone line, or PBX connection
Pilot number, accessible from outside
RJ-11C connector
9.
Translation Table
Translation table requirements for dialing restrictions
WARNING
: The following telephony components or services can take
from 4 to 6 weeks to order and install:
•
Network Telco Service (trunk lines, main phone number or combined
access numbers)
access numbers)
•
PBX specific hardware or software (Smart Blades, software upgrade)
•
Additional hardware (CSU, UPS)
13
If AMI is used, the number of zeros in a row may exceed the recommended Telco value of 15. This can happen if all
participants in the same meeting are on the same span. In that case, a 0s pattern could be sent to all channels at the
same time, exceeding the zero’s maximum. This, in turn, can lead to meeting participants being dropped by the
Telco from the meeting. Therefore, use B8ZS or Jammed Bit, if possible.
same time, exceeding the zero’s maximum. This, in turn, can lead to meeting participants being dropped by the
Telco from the meeting. Therefore, use B8ZS or Jammed Bit, if possible.
14
T1 facilities using D4 framing are susceptible to false triggering of “yellow alarm” signals. This false triggering can
lead to dropped calls. Conferencing applications are particularly susceptible to this problem with D4 framing. The
problem can occur when all 24 channels on a single span are in a conference and are carrying identical data streams.
D4 transmission equipment in the network can falsely interpret the identical data on all 24 channels as a “yellow
alarm” signal. For this reason, Latitude recommends configuring T1 spans for ESF framing.
problem can occur when all 24 channels on a single span are in a conference and are carrying identical data streams.
D4 transmission equipment in the network can falsely interpret the identical data on all 24 channels as a “yellow
alarm” signal. For this reason, Latitude recommends configuring T1 spans for ESF framing.