Hold queue on WAN interface

[rohit12ja]

The customer is getting a low download speed of around 2-4Mbps and the upload speed is around 58Mbps.

The link is 100Mbps.

On the WAN interface, we are not observing any drops but we had configured hold-queue on the WAN interface.

Would that affect the upload and download speed?

Also, can you explain how to calculate how much hold queue we need to configure?

hold-queue 4096 in

hold-queue 4096 out

[balaji.bandi]

we are not sure about the requirement, you intend to use Queue, since you have performance, I would suggest removing and testing it.

See you able to reach the expected delivered bandwidth. Once that is done, you define what you want to Q and prioritise the traffic.

Hold-Queu is explained well in this post :

https://community.cisco.com/t5/xr-os-and-platforms/hold-queue-in-command-on-ios-xr/td-p/2237021

Since you have not mentioned what Router Model and IOS code, what interface the Link connected - just for reference Troubleshoot and deploy of hold-queue :

https://www.cisco.com/c/en/us/support/docs/routers/10000-series-routers/6343-queue-drops.html

For better advice post-show interface config and output to the view of the interface.

[Georg Pauwen]

Hello,

slow download speeds could be related to MTU settings. Try and set theMTU to 1400 on the WAN interface, and the tcp adjust-mss to 1360.

If that does not help, post the running configuration (sh run) of your router...

[Joseph W. Doherty]

"Would that affect the upload and download speed?"

Possibly.  Generally, "in" queue size makes little difference.  "Out" can make a huge difference, especially if too little (unlikely as you don't see drops) or too large.

More over, as you note download speed appears to be the problem, the issue could very well be "upstream" of your device.

"Also, can you explain how to calculate how much hold queue we need to configure?"

For "ballpark" sizing, about half the size of the TCP's BDP.  That's to support a TCP flow at maximum possible data rate, but there are many, many "it depends" that might impact the routers queue size, including (but not limited to) the fact that generally we're dealing with multiple flows and/or flows between different hosts each of which have their own optimal BDP.