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RED/WRED

sarahr202
Level 5
Level 5

Hi everybody.

RED/WRED randomly pick packets and dropped when the threshold are reached. My question is : Is it  always a TCP packet or it could any packet?

Thanks

1 Accepted Solution

Accepted Solutions

Reza Sharifi
Hall of Fame
Hall of Fame

Hi Sarah,

So, apparently RED and WRED is more effective with TCP connections according to this document;

WRED is useful with adaptive traffic such as TCP/IP. With TCP, dropped packets indicate congestion, so the packet source will reduce its transmission rate. With other protocols, packet sources may not respond or may resend dropped packets at the same rate. Thus, dropping packets does not decrease congestion.

here is the link:

http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfwred_ps1835_TSD_Products_Configuration_Guide_Chapter.html

HTH

Reza

View solution in original post

3 Replies 3

Reza Sharifi
Hall of Fame
Hall of Fame

Hi Sarah,

So, apparently RED and WRED is more effective with TCP connections according to this document;

WRED is useful with adaptive traffic such as TCP/IP. With TCP, dropped packets indicate congestion, so the packet source will reduce its transmission rate. With other protocols, packet sources may not respond or may resend dropped packets at the same rate. Thus, dropping packets does not decrease congestion.

here is the link:

http://www.cisco.com/en/US/docs/ios/12_2/qos/configuration/guide/qcfwred_ps1835_TSD_Products_Configuration_Guide_Chapter.html

HTH

Reza

Thanks reza, i understand how red or Wred affect tcp traffic, however i am trying to find if wred or red pick tcp only or any traffic,

Thanks

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It depends on what traffic you're subjecting to WRED.  I.e. WRED doesn't, by itself, examine "kind" of packet.

For example, WRED will often, by default, apply different min/max limits depending on a packet's ToS.

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