Specifications

Chapter 6 Configuring VoIP
Configure IP Networks for Real-Time Voice Traffic
6-10
Catalyst 4224 Access Gateway Switch Software Configuration Guide
OL-2031-02
Figure 6-1 RTP Header Compression
You should configure RTP header compression if the following conditions
describe your network:
• Links slower than two Mbps
• Need to save bandwidth
Note Do not use RTP header compression on links faster than two Mbps.
Perform the following tasks to configure RTP header compression for VoIP. The
first task is required, but the second task is optional.
• Enable RTP Header Compression on a Serial Interface, page 6-11
• Change the Number of Header Compression Connections, page 6-11
Before RTP header compression:
20 bytes 8 bytes
20 to 160 bytes
12 bytes
IP
Header
UDP
RTP Payload
After RTP header compression:
2 to 4 bytes
20 to 160 bytes
IP/UDP/RTP header
Payload
12076