Slow Bandwidth

Question

We too have started having problems at certain times of day about a month ago when using scp to copy data from our remote servers. Unfortunately, the problem has progressed to always being slow.

We have two remote servers, one with Afterburst and one with VPSLime. Downloading from Afterburst seems to max out at 150Kb/sec. VPSLime used to get 1Mb/sec, but now gets just 40Kb/sec!

We had Afterburst look into the speed issue and they tested their connection to Comcast and sent me the following:

Traffic to your IP is passed off to your ISP (Comcast) 3ms rt away from your vps in the nap of the Americas exchange in Miami. It is highly unlikely there is an issue between us and entering comcast's network. I will run some tests tomorrow morning to ensure your vps is capable of reaching near gigabit speeds - I expect it will be. I have a strong feeling the issue is between you and Comcast's point of presence in Miami.

As some evidence that this isn't Afterburst's issue, but appears to be a peering issue with Comcast, we transferred files between the Afterburst and VPSLime servers and got 1Mb+/sec each way.

We're using scp to transfer files. Is scp being throttled recently?

Thanks!

griggs · Answer

More info (speeds are shown in bold below for both Afterburst's tests and our tests using our Comcast Business Internet connection). Summary, the connection to Afterburst seems throttled.

Afterburst did two tests:

[root@vps /]# wget -O /dev/null http://cachefly.cachefly.net/100mb.test
--2013-12-31 18:25:37-- http://cachefly.cachefly.net/100mb.test
Resolving cachefly.cachefly.net... 205.234.175.175
Connecting to cachefly.cachefly.net|205.234.175.175|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `/dev/null'

100%[======================================>] 104,857,600 66.0M/s in 1.5s

2013-12-31 18:25:38 (66.0 MB/s) - `/dev/null' saved [104857600/104857600]

And our own test file at 880mbps

[root@vps /]# wget -O /dev/null http://us.lg.afterburst.com/100MB.test
--2013-12-31 18:26:37-- http://us.lg.afterburst.com/100MB.test
Resolving us.lg.afterburst.com... 96.47.231.200, 2607:ff48:1:300::4c4:5b70
Connecting to us.lg.afterburst.com|96.47.231.200|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 100000000 (95M) [application/octet-stream]
Saving to: `/dev/null'

100%[======================================>] 100,000,000 110M/s in 0.9s

2013-12-31 18:26:39 (110 MB/s) - `/dev/null' saved [100000000/100000000]

We did the same tests from our Comcast Business Internet connection:

localhost$ wget -O /dev/null http://cachefly.cachefly.net/100mb.test

--2013-12-31 10:18:35-- http://cachefly.cachefly.net/100mb.test
Resolving cachefly.cachefly.net (cachefly.cachefly.net)... 205.234.175.175
Connecting to cachefly.cachefly.net (cachefly.cachefly.net)|205.234.175.175|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `/dev/null'

73% [===========================> ] 77,280,908 6.20M/s eta 5s ^C
localhost$ wget -O /dev/null http://us.lg.afterburst.com/100MB.test
--2013-12-31 10:18:57-- http://us.lg.afterburst.com/100MB.test
Resolving us.lg.afterburst.com (us.lg.afterburst.com)... 96.47.231.200, 2607:ff48:1:300::4c4:5b70
Connecting to us.lg.afterburst.com (us.lg.afterburst.com)|96.47.231.200|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 100000000 (95M) [application/octet-stream]
Saving to: `/dev/null'

2% [ ] 2,315,480 117K/s eta 11m 20s

It would be great for someone at Comcast to try the same test.

Thanks,

Ted

griggs

Slow Bandwidth

griggs