How to analyze hardware queue on cisco devices..

[mohammed hurais]

Hi Frens,

I am looking for a proper command to check or diplay hardware queues on cisco devices . Also what are these hardware queues actually..is it related to QOS?

Can any one please help me with this?

[tranminhc]

Hi mohammed,

In router, you can use command show controllers gix/x and find the tx_limited line. The number display how many packets the hareware queue can contain before other inqueue-packets droped by tail drop. Remember It count number of packets regardless how big packet is.

The default tx_limit number differ from various platform (gigabit or fastether interface).

Hardware queue play a very important role to QoS. You should understand clearly about QoS before customizing it. Making the number too low may help your QoS work effectively but cost router's CPU load hard. In the other hand, with the too high number, your HW queue will be too long and make a bad impact to real-time traffic (like audio, video...).

Hope this help

[Joseph W. Doherty]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Also what are these hardware queues actually..is it related to QOS?

They are hardware buffers.  It a dedicated queue of packets waiting to be transmitted.

They are simply FIFO, i.e. no QoS.  (When they overflow, excess packets are place into different queues, often to which QoS might be applied.)