DSCP field not tagged by GD

[Elandryl]

Hi,

First of all i whish you an happy new year.


I'm facing a weird behavior.

The installation is on G1.503.35, using multiple WAN to connect MG with GD-2 on branches offices.
All are using the same IP Quality of service Category and so the same diffServDSCP field.

On all GDs it' working fine, IP Packets are tagged using the DiffServ value except one GD.

In base configuration we select the value and the GD learn it from the OXE and apply this configuration.
We try to capture the input/output traffic using tcpdump on two GD (the first is working and the second not).
So on the first GD everything is tag using the diffserv from mgr.

The second GD isn't taging the diffserv at all.
We can see that the OXE is tagging his traffic to the GD (same thing, tcpdump from the OXE) but it's not tagged anymore when the GD receive it (maybe changed on the network).
I tried to switch the GD from IP Domain / Ip Quality to uncheck and check configuration but nothing changed.

So i think it was a network issue but sometime i'm quite sure you face this problem too, we have to point the issue on the network to the network team ...

Everything point to a network problem but the fact is that the GD isn't tagging his traffic to the OXE and she's supposed to, i don't know why and it's little disturbing.

So i'm searching how the GD learn that she need to use a diffserv value ?

Thank for reading me.

[murraya]

Hi, on the GD have you manually set the Diffserve in the setup menu?

[krzysioD]

of course: Restart the GD afterwards

[smileyman]

Hi anybody,

can somebody explain me, by the way, the difference between configuration via mgr (IP Quality of Service Categorie) and the config in the GD (mgconfig)?

Thankyou
smileyman

[murraya]

Not really sure but I always configure the QOS settings on the GD using mgconfig. I guess the settings in mge would not take effect util the GD is up whereas using mgcongig all packets are tagged straight away.

[krzysioD]

Try to play with this: put GD into automatic config (crystal no.) from MGR, 1st delete the DSCP...

then set everything (dscp, crystal no / mac ) from MGR.
then play otherwise: set crystal no with manual, and dscp in mgconfig.

there should be a diffrence and a field test will show you how it works.
one disadvantage: if you have many GD / phones, they will get binaries with dscp = 46 [EF, the default] so, if you have like small link to branch office, if 10 ip phones got reset with new binaries and GD, well, your 128 kbps link will be saturated for some short time and data packets will just drop if your switch and router does it's job properly ...

[Elandryl]

I already try to configure it in mgconfig, GD tag his packets, i can see it using tcpdump but OXE receive it without DSCP field.
One other point for the network issue

I can try it on lab KryzioD so no problem with phones nor other equipements.

Thank for your replies, i will see and get back.

[sipmotor]

Hello,

one thing at first:
the difference between setting dscp via mgconfig an mgr is, that the dscp-settings in mgconfig are only taken after reboot while getting the binaries via tftp. After that the mgr-dscp will be taken.
If you just have one IP-Domain, all dscp values are the same on every ip-device which is manageable.
I would set a network tap in front of the gd and trace some packets in a call after the reboot. Than you can be sure that the gd uses the dscp (or even not).

Good Luck