Simple way to prioritize a whole (untagged) VLAN?

[lorn10]

Hi all!

At this point follows now another simple beginner question. What is the easiest way to prioritize an untagged VLAN1?

I have here a quite simple topology with only three vlans, VLAN1, VLAN2 and VLAN3. The first VLAN1 is untagged while the other two are tagged.

After some search I have found a config example here: https://networkguy.de/vlan-based-qos-on-a-hpe-comware-switch/

However, I am not really sure if this is the right way to go in my case. My main switch is a 3Com 4800G PoE (JD011A) which is seconded by a 3Com Baseline 2928 (HP JE006A). The router is a HP MSR1002 (JG875A).

[akg7]

Hello,

Why are you priortizing the untagged vlan?

Are these vlans carrying voice traffic?

Thanks!

[lorn10]

Hi akg7

In my case VLAN1 is the main vlan of the company. VLAN2 contains all VoIP phones while VLAN3 (ACL-isolated) is for the guests. A simplified example can be found here: https://community.hpe.com/t5/Comware-Based/Config-migration-to-newer-Comware-versions/m-p/7093785/highlight/true#M12850

The reason to prioritize VLAN1 is because we have now installed two new Panasonic UHD TVs which supports the (European) DVB>IP feature (aka TV>IP). So one of the TVs is acting as a DVB>IP server while the other is the DVB>IP client. This makes it possible that the second client TV can be located anywhere; - it no longer needs a physical DVB-C connection. WiFi or LAN is enough to receive the whole DVB program (including all features) of the cable TV provider.

This works all in all really good, - but it may be recommended to prioritize the whole traffic in VLAN1 because the DVB stream content is very critical in regard to latency. The IEEE P802.1p spec defines several priority levels, in my case the following two may be applicable:

4             4             VI           Video, < 100 ms latency and jitter

5             5             VO         Voice, < 10 ms latency and jitter

Source: https://en.wikipedia.org/wiki/IEEE_P802.1p

[akg7]

Hi @lorn10 ,

Let me try to find the config for  3Com 4800G PoE (JD011A).

What is the current software version in devices?

Is it comware 5?

Thanks!

[lorn10 · Accepted solution]

Awesome, it works now almost perfectly!

However, it turned out that I really have looked at the “wrong side” of the underlying problem. The effective bottleneck was not the LAN part of my network; the bottleneck was the 2.5 meters WiFi distance between the Panasonic UHD TV and the Aruba AP-515 Wi-Fi 6 (802.11ax) Access Point.

So the solution was to look for a better setting at the Aruba access point. Originally I thought that the short (and direct) WiFi distance wouldn't have any impact. But it can be said that WiFi is a fundamentally problematic matter when the corresponding content is very critical in regards to latency like a DVB-stream. This may be the reason why Panasonic strongly recommends to use in conjunction with DVB>IP (aka TV>IP) always the wired LAN instead of WiFi. I can confirm this maybe really the better way to go, if a LAN connection is present. In my situation, this was not the case.

I solved the problem through enabling the WMM (Wi-Fi Multimedia Traffic Management) setting in the Aruba access point. This feature is available for all older WiFi standards up to 802.11n. An Aruba source which explains this setting can be found here: https://www.arubanetworks.com/techdocs/Instant_41_Mobile/Advanced/Content/UG_files/Voice%20and%20Video/WMM%20Traffic.htm

Back to the topic, the current (2020/2021) Panasonic UHD TV models only supports 802.11n (1x1 configuration), the maximum data rate is 150 Mbits. As mentioned, the data rate has no real relevance here; the latency is the essential point. The Aruba AP supports regarding the 2.4 GHz band a 2x2 configuration so the total theoretical available 802.11n rate is 300 Mbit which represents 100%. I have configured the WMM feature now as follow:

Video WMM, 20% percentage bandwidth Share, 56 DSCP Mapping
Voice WMM, 5% percentage bandwidth Share, 56 DSCP Mapping

After this I noticed an improved behavior at the Panasonic DVB>IP Client TV. Finally I upgraded the Aruba AP firmware from the more conservative production build 8.7.1.4 to the standard production build 8.8.0.1. And that gave in the end an additional tweak, - the DVB>IP connection works now rock-solid. No streaming pixel artifacts are present, - even the UHD test channel is working almost perfectly well.

So that’s it. This topic ended up becoming an Aruba thread instead of a Comware one.