VOIP QoS: working through wiki examples with no joy
RouterOS general discussion

1 post   •   Page 1 of 1
dcam
just joined
 
Posts: 9
Joined: Tue Oct 25, 2011 5:06 am

VOIP QoS: working through wiki examples with no joy

by dcam » Fri Nov 04, 2011 11:27 am

I have a wireless link between two buildings comprised of two RB411s (5.5, firmware 2.29), set up like in http://wiki.mikrotik.com/wiki/Transpare ... o_Networks

The internet gateway is a dd-wrt router with QoS enabled for SIP and RTP.

VOIP works consistently well when there is no other network traffic on the wireless link.

But VOIP suffers very badly when other traffic goes over the link, for example when viewing a youtube video, VOIP becomes impossible to understand.

In bridge mode, the firewall needs to be turned on using the options under the Settings button under the Bridge tab in the Bridge window, because otherwise mangle won't work to mark packets, so setting this up is a critical first step.

I've been installing the rules on the wlan interface at each end of the wireless link.

Looking at the examples from the wiki:

1. IP address based prioritisation as in http://wiki.mikrotik.com/wiki/Voip

Some changes required to the rules they provide:

Change the ip addresses 192.168.0.16 to the ip address of your VOIP box on the network.
Change ether3 to the WAN network interface
Change all the disabled=yes to disabled=no

Having made those changes, install the rules, and then run up winbox and view the Queue Tree tab of the Queues window. The queue tree entries are visible there, but you can see that no traffic causes any of the packet counts of the queues to change. In other words, the mangle rules are not working.

Experimentation shows that if the in-interface and out-interface options are removed from the mangle rules, then packet counts are recorded against the queues.

But having done this, VOIP audio during heavy traffic still is not comprehensible.

2. DSCP(TOS) based prioritisation as in first example in http://wiki.mikrotik.com/wiki/DSCP_based_QoS_with_HTB


Some changes required to the rules they provide:

Change ether1 to the WAN network interface
If the WAN network interface is a wlan, change queue=ethernet-default to queue=wireless-default
Change the max-limit of top node of the queue tree to suit your network
Change the max-limits of the other tree nodes to suit your network

Having made those changes, install the rules, and then run up winbox and view the Queue Tree tab of the Queues window. The queue tree entries are visible there, and you can see that the traffic does cause updates of the packet counts of the queues to change. And yes VOIP traffic in both directions is going under critical 46 as it has DSCP of 46 in each packet. Most other traffic goes under routine 0.

However I haven't had any success with solving VOIP stability problems with this setup. Viewing a youtube video while having a VOIP call still messes up the audio big time. I've tried lots of settings with various speed limits without success, and I don't really like having to manually configure the speed limits...I'd rather have the system prioritise the VOIP traffic over the other traffic, whatever the speed of the network.



Does anyone have any ideas about how to get VOIP properly working in a stable way?

1 post   •   Page 1 of 1

Who is online

Users browsing this forum: Bing [Bot], fpawczynski, Google [Bot], nz_monkey and 33 guests

It is currently Sat Dec 20, 2014 10:26 pm