CRTP Configuration Command Directory

debug ip rtp header-compression

ip rtp compression-connections

ip rtp header-compression

show ip rtp header-compression

 

This chapter describes CRTP commands. CRTP is used on the low-speed serial linkage. The command can be used for compressing the header of RTP packet to effectively lower the occupation of bandwidth. At the same time, due to the reduction in packet length, the delay of packet transit on the linkage can be shortened substantially.

debug ip rtp header-compression

[no] debug ip rtp header-compression

command mode:

global configuration mode

example:

Router#debug ip rtp header-compression

21:39:30: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30315, Gen = 0

21:39:30: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23507, Gen = 0

21:39:30: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30316, Gen = 0

21:39:30: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23508, Gen = 0

21:39:31: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30317, Gen = 0

21:39:31: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23509, Gen = 0

21:39:31: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30318, Gen = 0

21:39:31: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23510, Gen = 0

21:39:31: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30319, Gen = 0

21:39:31: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23511, Gen = 0

21:39:31: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30320, Gen = 0

21:39:31: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23512, Gen = 0

21:39:31: RHC Serial1/0: output COMPRESSED_RTP, conn 0, cksum 0x0000, seq 30321, Gen = 0

21:39:31: RHC Serial1/0: recv COMPRESSED_RTP, conn 0, cksum 0x0000, seq 23513, Gen = 0

The form below describes the explanation of the output of the command “CRTP debug”

Area

Explanation

21:39:31

Current time of system

RHC

RTP header compression

Serial 1/0

Interface number

Recvoutput

Input or output

COMPRESSED_RTP(uncompress)

Packet type

Conn

Connection number

Cksum

UDP check sum

Seq

RTP sequence number

Gen

Generation value of CRTP packet

 

ip rtp header-compression

This command is needed to use under interface configuration mode for activating CRTP on the serial linkage. The “no” format of the command can be used for forbidding CRTP.

ip rtp header-compression [{iphc-format | passive}]

no ip rtp header-compression

parameter:

iphc-format

Obeying CRT Pprotocol of rfc2507 IPHC standard

cisco-format

the format of IPCP negotiation packet that use the cisco format

passive

CRTP packet started to be transmitted after receiving CRTP packet of the opposite terminal.

 

default:

It is under forbidden state without configuring the command. When this command is configured, the default is passive in the case of without adding optional parameters.

command mode:

interface configuration mode

explanation:

Currently CRTP is supported only on the serial linkage of PPP encapsulation and will be extended to Frame RelayHDLC and ISDN port, etc. The command should be configured simultaneously on the two terminals of serial linkage, otherwise it will not work. Meanwhile, when the relative header of effective load of packet is relatively small, this protocol is quite applicable. However, when the header is far below net load, it will reversely add the processing spending of the router for the packet. Therefore, the protocol is used for transmitting the similar RPT packet on the linkage.

example:

Router_config#interface serial 1/2

Router_config_s1/2#ip rtp header-compression

Router_config_s1/2#ip rtp compression-connections 25

Router_config_s1/2#enc ppp

Router_config_s1/2#

ip rtp compression-connections

ip rtp compression-connections number

no ip rtp compression-connections

parameter:

number The maximum linkages of local-reserved CRTP

default:

15 connections

command mode:

interface configuration mode

explanation:

The number of RTP dialogue that is likely to occur simultaneously on the linkage can be estimated under general condition. It will be tight when the number of the configured connection is bigger than that of RTP dialogue.

example:

Router_config#interface serial 1/2

Router_config_s1/2#ip rtp header-compression

Router_config_s1/2#ip rtp compression-connections 25

Router_config_s1/2#enc ppp

Router_config_s1/2#

show ip rtp header-compression

show ip rtp header-compression [type number] [detail]

parameter:

type number     (optional) Interface type and interface number, such as serial 1/0 

detail    (optional) showing detailed information of each link

command mode:

global configuration mode

example:

Router#sh ip rtp header-compression

RTP/UDP/IP header compression statistics:

Interface Serial1/0:

Rcvd:           8900 total, 8858 compressed, 0 errors

                0 dropped, 0 buffer copies, 0 buffer failures

Sent:           8907 total, 8865 compressed,

                336735 bytes saved, 197685 bytes sent

Connect: 15 rx slots, 15 tx slots, 14 long searches, 1 misses

Router#

Keyword explanation of command display is made in the form below

Keyword

Explanation

Interface Serial1/0:

Interface number and interface type

Rcvd: total

Total of CRTP packet received at the port.

Compressed

Total of compressed CRTP packet

Errors

Total of erroneous packet received.

Dropped

Total of directly deleted packet received.

buffer copies,

The number of the packet that should be copied and saved.

buffer failures

The number of failures of applying for memory at the time of restoring normal IP packet.

Sent: total

Total of CRTP packet sent.

Compressed

Total of compressed CRTP packet sent.

bytes saved

Saved bytes

bytes sent

Real byte sent

Connect: rx slots

Total of data structure received.

tx slots

Total of data structure sent

long searches

It is needed to search in transmit data structure so as to determine the number of which to be used.

Misses

Search the number of failure of data structure.