MX84 limit client bandwidth to reduce VoIP problems

[Sam-I-am]

Hello,  

We are new to Meraki Firewalls and are attempting to understand how to create particular bandwidth pools for clients to limit VoIP issues.

We currently have 2 WANs, a 50/50 Fiber (for clients) and a 50/10 Coax (for backups).  We are not load balancing and the office has 55 users.

We originally attempted to allow unlimited use per user setting our SIP voice to High priority, DSCP tagging it as Real Time, and setting everything else as Normal but found that this maxed out our bandwidth causing VoIP issues.

We have also attempted to add a per client limit below our bandwidth maximum but found that even allowing more bandwidth than our VoIP system requires we still had VoIP problems. 

We have begun using the per client limit in the MX84 and have found that this eliminates the VoIP and bandwidth issues but this also severely limits users as we cannot apply enough bandwidth per user for acceptable internet use.  

With our last Firewall we were able to limit users to pull from a bandwidth pool that was below our maximum bandwidth capacity to guarantee that VoIP would always have bandwidth. 

Does the Meraki allow for this?      

[AndrewR · Accepted solution]

Hi, I don't believe you can create what you are calling, a "bandwidth pool" on an aggregate basis. You can only set bandwidth limits on a per-client basis, not a per-group or per-pool basis.

The one exception to this that I am aware of is if you are running any Meraki wireless AP's, you can set a per-SSID bandwidth limit. I think that's kind of what you're wanting to achieve, but on the wired LAN. Here's a reference article, but still, not necessarily what you're asking for. Global Bandwidth Limit Considerations

Other measures you can take to improve performance:

1. Do you have your VoIP traffic running on its own dedicated voice vlan? If not, I recommend doing so. This will give you some more granular controls, optimizations, and minimize broadcast traffic interference with your VoIP traffic.
2. You could consider getting more prescriptive about what you are putting out over the fiber WAN vs. the coax WAN, and with Traffic Shaping, try to carve out lower priority traffic to the coax? There's A LOT you can do here. I recommend doing some data analysis first based on what historical data your MX84 captures, to help inform effective Traffic Shaping rules. 30 days of data is probably a good starting point.
3. Lastly, if you leave your clients set to unlimited bandwidth, I don't think it matters what you do with anything else, you will always risk maxing out your 50/50 connection. I highly recommend a sensible per-client limit, but then layering in some basic traffic shaping that places more restrictive bandwidth limits on select, lower-priority services, and/or make exceptions to the per-client limit for high-priority services and/or clients (see Group Policies).

To give you some context of where I am coming from, we have two WAN's of similar size to yours, but with an average of 300+ clients connected. 

[Sam-I-am]

Hello Andrew, 

Thank you for the reply and article, it was very helpful.

I was afraid that lack of ability to limit users as a whole might be an issue.  I do not have VoIP on it's own VLAN but will look into separating it  I have made some changes based on the article you sent along with some other ones that I came across regarding Traffic shaping and packet prioritization and believe that we may have been able to find a good medium (time will tell).

I will look further into pushing more lower priority traffic across Coax as well. 

Thank you again for the reply and the useful information.