Cisco 1700 series Configuring - Page 24

Browse online or download pdf Configuring for Network Router Cisco 1700 series. Cisco 1700 series 34 pages. Secure firewall management center
Also for Cisco 1700 series: Regulatory Compliance And Safety Information Manual (45 pages), Manual (15 pages), Configuration Manual (25 pages), Application Note (41 pages), Hardware Troubleshooting (12 pages), Overview Manual (13 pages), Manual (5 pages), Quick Start Manual (6 pages), Hardware Installation Manual (46 pages)

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Configuring Quality of Service Parameters

The basicpremise of cRTP is that although several fields in the IP, UDP, and RTP header change from

packet to packet, the differences in these fields from packet to packet are constant. The compression

scheme in cRTP encodes the header to reduce the size of the information to be transmitted. With cRTP,

a 40-byte IP, UDP, and RTP header of a VoIP packet can be compressed to 2 to 4 bytes per packet,

yielding approximately 11.2 kbps of bandwidth for a G.729 codec call with RTP.

cRTP can be applied to an ATM link through cRTP for MLP over ATM, or through cRTP for PPP over

ATM.

Configuration Example

The following are examples of cRTP for MLP over ATM, and cRTP for PPP over ATM. The ip rtp

header-compression command sets cRTP.

cRTP Using MLP over ATM

interface Loopback1

ip address 10.0.0.9 255.255.255.255

interface ATM0/0

no ip address

no atm ilmi-keep-alive

dsl operating-mode auto

interface ATM0/0.1 point-to-point

pvc 0/33

ip 10.0.0.10

vbr-rt 320 320 30

tx-ring-limit 3

protocol ppp Virtual-Template1

interface Virtual-Template1

bandwidth 320

ip unnumbered Loopback1

ip tcp header-compression iphc-format

service-policy output ADSL-2

ppp multilink

ppp multilink fragment-delay 4

ppp multilink interleave

ip rtp header-compression iphc-format

cRTP Using PPP over ATM