mark packet in a switch possible?

RouterOS General
1

hi, we have a rb3011 as our main routeur, we ran cables to a rb750 upr2, then to antoher and finaly to a rb941 2nd.


in the 941, we have a voip phone that is connected to. We made simple qos rule in both routers, (queue tree, mangle rules to mark packet that goes to the VOIP provider). So that is fine.

Since there are trafic that come from other branch of the network and goes to the rouer, we would be able to make a kind of qos in our switch. Marking connections, packet etc. Is it possible enven if rb750 upr2 are set as ‘‘switch’’ mode ?


thank you.

2

Marking packets and connections is an router internal feature and have no consequences “on the wire”.
IPv4 TOS/DSCP fields on the other hand could be used. But for this to happen, I think the Phone itself needs to be able to set the TOS/DSCP field, since it is a L3 feature, while switches work at L2.

3

There’s 802.1p for marking packets for QoS at the L2 when using VLANs.
https://en.wikipedia.org/wiki/IEEE_P802.1p

I see that Cisco Catalyst switches support 802.1p. I am not sure about MikroTik switches though.Edit: It appears that it is supported via bridges. https://wiki.mikrotik.com/wiki/Vlans_on_Mikrotik_environment
I guess with the new bridge/switch implementation on v6.41 that would be supported on switches too.

I believe most VoIP telephones do support setting at least ToS/DSCP anyway.

4

thank you.


Need I consider VLAN in my network? Make voip trafic in vlan would help Quality (voice cutting, delay, etc.) Am I right?

Some engineer here told me that there is almost no effect on voice quality, VLANs only make it more secure and easier for trouble shooting. I’m a bit confused.

5

He is correct. VLANs do not change the VoIP data in any way.

6

thx for fast reply,

In layer 2, What can I do roughly to make voip quality better using mikrotik gears?



For exemple, I have 1 client with a 941 router and 1 x ATA cisco SPA112.
That goes to A 750upr2 (switching mode)
follow a crs112 switch
then to my ccr1009 that is connected to my internet provider (optical service)

Current problem is delay echo and cuting voice. Directly to my ISP there is no problem.



Both 941 and ccr1009 :
I made a firewall accept rule to accept all trafic from my provider.
2 mangle, where tagging inbound and outbound voip trafic from my provider
2 mangle, where tagging inbound and outbound all other trafic
and
queue tree, to make VOIP trafic priotity 1 and all other traffic to 8. Inbound and outbound


You talked about TOS and DSCP earlier, is it usefull in L2?