There is a significant improvement in the application of MIR and burst coming in 14.2 for 450i. Historically we consumed data at the achievable rate and refilled at a fixed rate (once per second). So this lead to very bursty consumption of burst bucket and MIR and quiet link for remainder of the refill duration. We have greatly increased the granularity of the refill on 450i as the HW is considerably more capable and able to handle it. This leads to much more rapid refill events which smooths out the consumption.
For an example, here are two speedtest graphs showing a similar outcome of a ~20M MIR, but you can clearly see how the old method was bursty consumption and the new method is smooth. I think that could definitely cause impact on something like voip. [cid:[email protected]][cid:[email protected]] We will look at doing this on the 450, but it would affect PPS so we need to analyze the impact, but it definitely will be there for 450i in 14.2 release. Regards, -Aaron -----Original Message----- From: Af [mailto:[email protected]] On Behalf Of Timothy Alexander Sent: Tuesday, April 19, 2016 1:52 PM To: [email protected] Subject: Re: [AFMUG] High Priority Uplink / Downlink We use 100 kbits per call session of G711U. We took a while to get a good working config on junos to make sure only voip traffic comes in to the SM tagged for high priority. The SM only goes by the Priority Precedence selection to check either 802.1p or DSCP to determine transmit channel and you need to make sure inbound ethernet traffic to the SM is tagged correctly so that voip, and only voip, ends up in the high priority channel. We also ran into issues with burst allocation and burst rates. In order for the high priority channel to work correctly on 450 platform we found you must set the Sustained Uplink/Downlink Data Rate and the Uplink/Downlink Burst Allocation to be the same (customer regular bandwidth + high priority bandwidth) and the Max Burst Uplink/Downlink Rates to double the Total Sustained Uplink/Downlink. We confirmed in extensive testing that if we simply enable a high priority channel on a normal customer, when the user maxes his upload or download we see packet loss on the high priority channel even when the upload/download is all low priority traffic and the high priority channel is not being 100% used. Why is this? We're not sure but our network engineers did pretty extensive testing and we consistently saw packet loss when configured with a high priority channel and a "normal" customer deployment of Sustained Down 4 Mbit / Sustained Up 1 Mbit, Downlink Burst Allocation 120000 and max burst downlink of 10000. Timothy Alexander Amplex Internet www.amplex.net<http://www.amplex.net> [email protected]<mailto:[email protected]> >>From: Brian >>Sullivan<[email protected]<mailto:[email protected]>> >>To:"[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> >>Subject: [AFMUG] High Priority Uplink / Downlink What do other >>operators set for the High Priority Uplink / Downlink CIR that works best for VOIP?
