I don't have an answer to the question on QCI 7 vs QCI 6. I was curious how you configure the UE to classify upload traffic. I noticed the default config on both 7000 and 8000 is set to use DSCP 6 for management, so I made my dedicated bearer use DSCP 6. Is that enough, or is there more to it?
I could probably read the manual and figure this out, but I was just stabbing at it in my spare time :) ------ Original Message ------ From: "Nathan Anderson" <[email protected]> To: "[email protected]" <[email protected]> Sent: 1/31/2017 3:20:34 PM Subject: [Telrad] QCI levels and latency >All, > >We recently implemented iPCRF on our EPC to great effect. We added a >QCI 1 profile that we apply to our dedicated bearer, and are >prioritizing our VoIP service using that. So that we can easily see >and verify the effectiveness of this, we also started sending ICMP over >the same dedicated bearer. Average latency and jitter to CPEs dropped >like a rock right after we did that, so it is clearly working. > >When our ENBs start to become moderately busy, we still notice that RTT >for traffic on the default bearer can become both exceptionally latent >and jittery. This is easy to see if we run a constant ping to a CPE >and then stop prioritizing ICMP to that CPE in the middle of the ping >test. Ping jitter goes up significantly almost immediately. When we >prioritize ICMP, all we end up doing is masking that problem. > >Unfortunately, release 6.6 only allows for one dedicated bearer, so we >can't classify different types of traffic across multiple QCI levels in >order to try to help deal with this better. But after looking at the >various QCI levels that are defined in the LTE spec >(https://en.wikipedia.org/wiki/QoS_Class_Identifier), I am wondering if >there isn't a short-term answer to this problem while we wait for >multiple dedicated bearer support. Specifically, I see that each level >also has a defined "packet delay budget". QCI 6, the default pick for >the default bearer, has a PDB of 300ms. What would happen if we were >to, say, switch to using QCI 7, which has a PDB of 100ms, for our >default bearer? Would we actually see an overall improvement in RTT? >And if so, would it be at the expense of anything/what would be the >downside(s)? (For example, would overall throughput end up taking a >hit because it is trying to service UEs less efficiently so that it can >make good on the latency budget?) > >I'm curious to know if anyone has tried this. > >Thanks, > >-- >Nathan Anderson >First Step Internet, LLC >[email protected] > >_______________________________________________ >Telrad mailing list >[email protected] >http://lists.wispa.org/mailman/listinfo/telrad > _______________________________________________ Telrad mailing list [email protected] http://lists.wispa.org/mailman/listinfo/telrad
