*PRiority (config-if)#priority-group group_number(1-16) (config)#priority-list list-number protocol protocol-name {high medium normal low} queue-keyWord keyword-value list-number interface interface-type interface-number {high medium normal low} (config)#priority-list list-number default {high medium normal low} *optional commands !command to change the max number of packets in each queue. (config)#priority-list list-number queue-limit high-limit medium-limit normal-limit low-limit !default 20 40 60 80
!queue-keyword values fragmens-->number of fragments gt-->port num lt-->port num list--->access list tcp-->port num udp-->port num
*Custom (config-if)#custom-queue-list list_number(1-16) (config)#queue-list list-number protocol protocol-name {high medium normal low} queue-keyword keyword-value (config)#queue-list list-number interface interface-type interface-number queue-number (config)#queue-list list-number default queue-number -optional commands !specify the max number of packets for a particular queue (limit-number 0 - 32,767) (config)#queue-list list-number queue queue-number limit limit-number !if max number of packets are set too low you will drop the excess traffic!!!! !default limit-number is 20 (config)#queue-list list-number queue queue-number byte-count byte-count-number !default byte count is 1500
*debug commands show queueing show queueing {int custom priority fair } show interfaces
Compression
One of the most important points in compression theory is that there exists a theoretical limit, known as Shannon's Limit, to how mUCh a given source of data can be compressed. Beyond that point, it is impossible to reliably recover compressed data.
Compression is not a bandwith replacement only a temporary fix!
You should not compress:
Already compressed data
Encrypted data
High speed links
Compression is typically either a cpu or memory intensive opreation and must be preformed on both ends of the connection.
Types of compression
Link compression (also known as per-interface compression, mainly point to point links because the packet is non-routable once compressed)
Payload compression (also known as per-virtual-circuit compression, can be used any situation)
TCP header compression (used when you have lots of small ip packets)
Three types of link compression
predictor - memory intensive
stac - cpu intensive
mppc- microsoft point-to-point compression- used in tunneling ppp across a virtual connection (PPPTP- Point-to-Point Tunneling Protocol) (config-if)#compress {predictor stac mppc}
Payload compression used mainly in
Frame relay
SMDS
ATM (config-if)#compress payload-compress
TCP header compression
used mostly in PPP connections (config-if)#ip tcp header-compression
