QoS Egress going over the limit.

PeterUK

So I done the test with my GS2210 does KB/s so I converted to Kbps with V4.25 and V4.31 egress set to 3008Kbps and doing downloading and uploading at the same time.

V4.25

V4.31

are you going to believe me now.

Zyxel_Cooldia

Hi @PeterUK,
I am doing the lab testing again on V4.25 and V4.31, there is no major difference in terms of result from both versions.
Here is the lab testing topology:
PC-----------USG---------Speed test server
USG run as Bridge mode, Interface Wan and Lan set to Egress 3008Kbps.
Test procedure:
1)    Run the speed test
2)    Monitor the speed test server up/down value=> Both V4.25 and V4.31 is within the Interface Egress limitation.
3)    Monitor on testing PC up/down value => Both V4.25 and V4.31 are going to over the BWM limitation, but the peak is only for a short time(3.1/3.3Mbps), it should be okay in this case
4)    Monitor the port status, both V4.25 and V4.31 are over the limitation.(V4.25 is 3.64Mbps / 2.89Mbps, V4.31 is 3.53Mbps /2.90Mbps)
In this testing, I capture the packets on USG Wan1 interface, assume my PC IP is 192.168.10.33, apply the filter “!ip.addr eq 192.168.10.33” on Wireshark, we can observe that physical interface traffic is not just only from my PC 192.168.10.33, It also include other traffic.
However, we are still curious about the value between V4.25 and V4.31. Can you send me the device configuration file and USG wan interface packets trace during the speed test for analysis(V4.25 and V4.31).

PeterUK

Zyxel_Cooldia said:
USG run as Bridge mode, Interface Wan and Lan set to Egress 3008Kbps.

Only set the WAN to 3008Kbps set the LAN to 65536 Kbps

If you set it up like this you be able to see the USG Egress rate which will be more accurate

PC-----------USG---------GS2210 for Port Status showing Tx/Rx KB/s---------Speed test server

I know exactly why its going over the limit if you follow me, when doing a upload the ACK's for the download that are being sent are not limited for the upload causing the Egress to go over the limit so setting the LAN to 3008Kbps you would not see the problem then if its set at  65536 Kbps (for the LAN) as their are more ACK sent at a high download which the combination makes it go way over the Egress limit.

The goal for me is not to go over my ISP non-QoS limit 5250000 bps or 5126.95Kbps I've now found that V4.25 set the limit at 4864Kbps with a rule in with BWM enabled.

BWN type = shared

user = any

incoming Interface = any

outgoing interface = any

source = any

destination = any

service object a group with (any TCP, any UDP, ICMP)

guaranteed bandwidth

Inbound 128kbps check box maximize bandwidth usage

outbound 128kbps check box maximize bandwidth usage

which limits under my ISP limit and V4.31 does not and goes over.

The reason I'm saying limit WAN to 3008Kbps is my ISP limits at 5126.95Kbps so I can see at 3008Kbps how much it going over by in V4.31.

and the Egress should never go over the set limit which it does not when doing a upload only but should not go over the limit when downloading and uploading either. 

PeterUK

To keep everyone in the loop it turns out there was a change between V4.25(AAKY.1)C0 and V4.30(AAKY.0) for BWN and it happens with NAT mode too. To improve performance they bypass small ACK packets for a download so it don't get BWN or QoS which for the most part may not seem a problem that is until you download and upload at the same time. So this is being looked into not sure when or if this will be addressed.       

PeterUK

Just tried 4.33(AAKY.0) on my USG60 and the iusse is still their so rolling back to V4.25(AAKY.1)

Zyxel_Charlie

@PeterUK

Regarding to this case,
We have done some changes from 4.25 to 4.3X to let device's performance get better.
Therefore, the behavior as below

-V4.25 

 The tcp ack traffic jump into BWM chain for operation.

-V4.3X

 The tcp ack traffic will not jump into BWM chain for operation, says, the ack packets bypass directly.

Comparing the behavior of both version, v 4.3X has better performance than v 4.25, because of fast response the ack packets to service side. (Even set the TCP ack to be first priority in BWM chain, the performance still be affected)

We currently have no plan to change the behavior back to the previous version(4.2x)

Charlie

PeterUK

So what do you expect me to do then? My ISP does not bypass directly ack traffic I have a 5Mb upload for all traffic limiting under this in V4.25 works fine so do you expect me to limit under haft of my 5Mb!? Better performance is not better if you break all the rules.

Zyxel_Charlie

@PeterUK
Regarding to the case of BWM,
we will enhance this feature on further release, and the schedule will be around Q4.
Charlie

PeterUK

Not Q4 yet but look forward to a fix as I just got a ZyXEL VPN300 to replace as my main QoS which has the same issue so having to limit my upload speed to allow for the download sending ACK back when doing uploading and downloading at the same time.

Zyxel_Cooldia

Hi @PeterUK

We apologized that the enhancement will be postponed to 2020 due to the schedule adjustment. However, we’re sure that this enhancement was put in our release plan.