About Cisco Ipvc 3500 Series Gateway Call Bandwidth Overhead; About Peer-To-Peer Connectivity - Cisco 3521 Administrator's Manual

Chapter 1 Overview of the Cisco IPVC 3500 Series Gateway
Table 1-10
Call Type
voice (64 Kbps)
2B video (128
Kbps)
6B video (384
Kbps)
12B video (768
Kbps)
Note Enabling ISDN-to-IP DTMF detection in the Cisco IPVC 3526 PRI Gateway for video calls reduces the
number of supported calls by half.

About Cisco IPVC 3500 Series Gateway Call Bandwidth Overhead

According to the H.320 standard, the available bandwidth allocated to a call at any given bit rate will
always be slightly less than the stated maximum for the following reasons:
•
•
•
For example, a call at 384 Kbps actually has only 363 Kbps available to it. Control and error correction
account for the remaining 21 Kbps

About Peer-to-Peer Connectivity

The Cisco IPVC 3500 Series Gateway supports the following types of connectivity to the IP network
•
•
Administrator's Guide for Cisco IPVC 3521 BRI Gateway, Cisco IPVC 3526 PRI Gateway, and Cisco IPVC 3540 PRI Gateway
OL-7995-01
Cisco IPVC 3526 PRI Gateway and Cisco IPVC 3540 PRI Gateway Call Handling
Capacity
Maximum
Number of Calls
Using 1 x E1 PRI
Line
30
15
5
2
All stated maximum call bandwidths include provision for control, audio, video, and data traffic.
Video traffic on the ISDN side contains additional bits for error correction purposes which also
consume bandwidth. Video traffic on the IP side does not include this additional load.
Opening an audio channel further reduces the bandwidth available to the video traffic.
Through a gatekeeper
Directly to a peer device such as Cisco CallManager without the need for a gatekeeper.
About Cisco IPVC 3500 Series Gateway Functionality
Maximum
Number of Calls Maximum Number
Using 1 X T1 PRI of Calls Using 2 x E1
Line PRI Lines
23 60
11 30
3 10
1 5
Maximum Number
of Calls Using 2 x T1
PRI Lines
46
23
7
3
1-21