Cisco RV180 QOS and Bufferbloat

[JWadle]

I have just installed an RV180 router for a new customer. The customer has Comcast Internet at 180Mbps. With default settings, the router LAN speed tests at 180Mbps down / 12Mbps up, but with a "bufferbloat" rating of "F".

In the past (with other routers), I have been able to reduce bufferbloat by setting QOS with speeds limited to 95% of maximum (e.g. 170Mbps). Typically this improved bufferbloat to B with very little loss in speed.

I tried this with the RV180, but found that the QOS settings only allow a max speed of 100Mbps. Using this max, my download speed is reduced to 60Mbps and the bufferbloat improves to C.

Why are QOS max speeds limited to 100Mbps on a gigabit router?? What do you recommend to reduce bufferbloat but still maintain speed?

 

[Nullity]

QoS usually negates off-loading, so then the CPU must do all the work, sometimes severely limiting speed if the CPU is slow and/or if the device relied heavily on off-loading.

You should be able to apply QoS to the 12Mbit upload, at the least.

 

[System Error Message]

none of the VPN routers actually perform well because of the platform. Try a different platform. the Cisco RV series is actually worse than asus now and is a stain to what cisco should be. The clock speed of the cisco RV series is also worrying as well which is why you are getting low throughput with QoS, the device doesnt have enough CPU to perform QoS at WAN speed.

 

[Trip]

Following Nullity and SEM, I'd return the RV180 and start from scratch if possible. The unit just simply doesn't have the CPU nor a current-enough queuing/shaping approach to really be relevant in most higher bandwidth applications requiring effective QoS. I'd assume you have no intention of jumping into big-boy Cisco gear for this project (ISRs and/or L3 managed switches), so I'll suggest some lighter-class enterprise stuff below...

Unless you specifically require classing and fine-grained manual adjustment, I find QoS based on the "knobless" fq_codel to be the easiest, fastest and most effective at making a measurable impact on traffic. For 200 Mb/s aggregate, you're going to want at least a higher-clock MIPS device, such as a Ubiquiti EdgeRouter Pro, or for more headroom, an x86 box running a Linux router distro such as IPFire. That will let you hit your 200Mb mark, with a bit of extra cpu to run other rules and/or services on the box.

If you're requiring more explicit QoS with manual control at every level and you have the networking chops to set it up, the best bang for the buck in the embedded space may be Mikrotik, whose CCR1009 will handle that amount of QoS with ease, but as I said the QoS requires manual building per this guide -- most definitely *not* for rookies or the unwilling.

Hopefully some of that helps.

 

[System Error Message]

for the 200Mb/s mark of QoS and firewall the choice is between the ER-8 and above or mikrotik's RB1100AHx2 or CCR1009. Fan noise from mikrotik may be a downside but they dont rely on hardware processing so you can trust their numbers more than ubiquiti.

The other solution would using x86. All solutions require more skill to set up but they will achieve that speed for sure. Im not too sure about Ubiquiti in getting 200Mb/s though but some have said that the ERPRO gets up to 300Mb/s but it does however use the same platform as the cisco rv (so it may not help with bufferbloat), only faster clocked and it still relies on hardware acceleration as well.

My recommendation would be to go with mikrotik or x86 for low cost for the consistency of software throughput. professional cisco and juniper is a viable option for price and support and there is peplink which is also a pricey option with good support.

If you have internet through fibre optics, getting a router with SFP and the module for it will also help in eliminating buffer bloat if the router is good.