Didn't find what you were looking for?
We have advanced search options to make it easier to locate posts, questions and answers on this community.
More information can be found at Advanced Search Options
If you are looking for something specific, please check if someone else has already asked or answered the same question.
Peering with AT&T and long trips through Charter's network

I have Spectrum 1G/40M DOCSIS 3.1 at the moment at one premises (MI), and AT&T fiber 2G at the other (CA).
What I am finding is that essentially "last mile" speeds on each end are fine, but the actual throughput between the two is pretty miserable. I'm doing cross-premesis backups over VPN, so I don't particularly care about the latency, but I'd expect to get better than 150 Mb/sec, at least in the one direction that isn't across the 40MB upload over DOCSIS.
From Spectrum to AT&T:
2 syn-072-031-150-017.inf.spectrum.com (72.31.150.17) 17.387 ms 9.379 ms 9.984 ms
3 lag-60.hcr02fmhlmiof.netops.charter.com (72.31.205.62) 10.190 ms 10.984 ms 12.018 ms
4 lag-22.detr01-cbr2.netops.charter.com (71.46.180.76) 17.016 ms 18.227 ms 17.990 ms
5 lag-100.detr01-cbr1.netops.charter.com (72.31.205.107) 19.965 ms 18.414 ms 14.879 ms
6 * lag-110-10.chcgildt87w-bcr00.netops.charter.com (24.27.236.0) 47.398 ms *
7 lag-0.pr2.chi10.netops.charter.com (66.109.5.225) 19.778 ms 24.023 ms
lag-401.pr2.chi10.netops.charter.com (66.109.0.109) 28.006 ms
8 syn-024-030-201-070.inf.spectrum.com (24.30.201.70) 24.284 ms 21.314 ms 23.838 ms
9 * * *
There the traceroute just dies for no reason I can discern.
From AT&T to Spectrum:
2 162-231-240-1.lightspeed.sntcca.sbcglobal.net (162.231.240.1) 3.459 ms 5.060 ms 2.209 ms
3 71.148.149.126 (71.148.149.126) 2.070 ms 4.046 ms 2.897 ms
4 * * *
5 * 32.130.91.81 (32.130.91.81) 3.744 ms 3.993 ms
6 lag-1107.pr1.sjc10.netops.charter.com (24.30.200.141) 6.928 ms 5.242 ms 7.429 ms
7 * lag-13.snjucacl67w-bcr00.netops.charter.com (66.109.5.132) 52.075 ms 54.173 ms
8 * * *
9 lag-14.chcgildt87w-bcr00.netops.charter.com (66.109.6.15) 51.971 ms 51.338 ms 53.850 ms
10 lag-10-10.detr01-cbr1.netops.charter.com (24.27.236.1) 56.142 ms 56.210 ms 57.497 ms
11 lag-100.detr01-cbr2.netops.charter.com (72.31.205.106) 58.898 ms 61.558 ms 59.039 ms
12 lag-1.hcr02fmhlmiof.netops.charter.com (71.46.180.77) 60.936 ms 59.545 ms 59.214 ms
13 syn-072-031-205-063.inf.spectrum.com (72.31.205.63) 59.249 ms 59.743 ms 60.198 ms
And the traceroute dies there.
But what the second traceroute shows is that getting from AT&T to Charter happens pretty darned quickly. But the journey through Charter to the other end seems pretty torturous.
Comments
-
Just curious if you could clarify what you mean by "actual throughput" and by what means & measure you're seeing "150 Mb/sec."
0 -
1
-
Guessing your backup is running high compression? Likely not a constant stream of data, but coming periodically in small chunks and getting those weird sort of RTS/CTS handshakes each cycle.
If so, may be better off backing up to a scratch disk, then pushing the final backup afterwards, or otherwise use a drive that's set to synch automatically.
0 -
@HT_Greenfield 150 Mb/sec or so is what I get from iperf in the CA → MI direction (because the other way is going to be limited by the 40M upload speed).
1 -
@raist5150 The actual backup is Apple Time Machine, so I do not believe it's compressed, and it's just SMB. That said, that's not how I'm measuring the throughput. I'm using iperf for that.
0 -
Heard that. No idea how iPerf imputes "bandwidth" in Mbits/sec from transfer rate in MBytes/sec but no reason to doubt that it does it well. What kind of "bandwidth" according to iPerf3 do you get from the iperf.he.net Hurricane Electric public iPerf3 server in Fremont to your host in Michigan versus to your host in California both with and without VPN?
0 -
Well, testing against iperf.he.net would by necessity not use the VPN, since the VPN is just a tunnel between the two premises.
I had been using just plain iperf. It showed poor results from CA to HE, so I installed iperf3 and got 2.15 Gb/sec - so almost the full pipe.
Going from MI to HE, I get 30 MB, but that's because it's throttled by the cable modem upload there. Using -R, I get about 400 Mb/sec.
All that said, iperf3 to HE seems to be preferring IPv6. The VPN is ipv4 both inside and out. Even so, the bandwidth from HE to MI is less than half the cable modem wire speed in that direction (albeit being 2000 miles instead of 50).
I repeated the test from CA to MI with iperf3 and got the same results - ~180 Mb/sec.
0 -
I wondered if this was a v4 vs v6 issue, so I temporarily made a firewall rule to expose iperf3 from the Michigan side with both v4 and v6 and tested outside the VPN. I got the same result - around 450 Mb/sec with both protocols, but still about 185 Mb/sec through the VPN.
So clearly the VPN is having a pretty major impact. It's wireshark running on an Asus BQ16 on both ends. Now, the BQ16 is kinda a heavyweight, so I'd be a bit surprised if wireshark on it would affect it so much, but I don't have a whole lot else to hang it on, I suppose, except for wondering where the other 600 Mb/sec is going on the trip from California to Michigan.
0