Slow Upload Speeds via SCP


#1

While Dreamhost says there is no throttling, I am experiencing something.

When uploading a file via FTP or SCP, I see upload speeds that quickly drop to a sustained 80 kB/s.

However, if I log in to my Dreamhost server through SSH and use wget to fetch the file off my computer, I see sustained upload speeds of about 500 kB/s for the very same file, which is the kind of speed I expect to achieve for an upload.

What’s going on there?

Here’s a traceroute in case that helps.

[code]Tracing route to glowingpixel.com [69.163.242.240]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms 10.0.1.1
2 7 ms 7 ms 7 ms 10.157.192.1
3 8 ms 7 ms 8 ms dtr01fntnmi-gbe-1-20.fntn.mi.charter.com [96.34.32.162]
4 8 ms 9 ms 9 ms csw01dvsnmi-tge-4-4.dvsn.mi.charter.com [96.34.32.102]
5 12 ms 12 ms 10 ms dtr01dvsnmi-tge-0-1-0-0.dvsn.mi.charter.com [96.34.32.180]
6 18 ms 11 ms 11 ms crr02sgnwmi-tge-0-7-0-7.sgnw.mi.charter.com [96.34.33.135]
7 12 ms 14 ms 15 ms bbr01sgnwmi-tge-0-5-0-2.sgnw.mi.charter.com [96.34.1.182]
8 17 ms 23 ms 23 ms bbr01aldlmi-tge-0-1-0-6.aldl.mi.charter.com [96.34.0.54]
9 22 ms 24 ms 23 ms bbr01chcgil-tge-0-1-0-7.chcg.il.charter.com [96.34.0.160]
10 18 ms 20 ms 19 ms prr01chcgil-tge-1-1.chcg.il.charter.com [96.34.3.9]
11 20 ms 19 ms 19 ms be-10-805-pe01.350ecermak.il.ibone.comcast.net [75.149.231.205]
12 20 ms 19 ms 19 ms pos-2-5-0-0-cr01.350ecermak.il.ibone.comcast.net [68.86.87.125]
13 23 ms 22 ms 21 ms pos-1-7-0-0-cr01.chicago.il.ibone.comcast.net [68.86.88.45]
14 56 ms 59 ms 54 ms pos-1-8-0-0-cr01.denver.co.ibone.comcast.net [68.86.87.222]
15 56 ms 55 ms 56 ms pos-2-15-0-0-cr01.dallas.tx.ibone.comcast.net [68.86.85.174]
16 89 ms 87 ms 92 ms pos-0-11-0-0-cr01.losangeles.ca.ibone.comcast.net [68.86.87.37]
17 89 ms 88 ms 89 ms as26347.losangeles.ca.ibone.comcast.net [75.149.228.206]
18 171 ms 206 ms 299 ms ip-66-33-201-114.dreamhost.com [66.33.201.114]
19 90 ms 91 ms 90 ms apache2-whippit.gretsch.dreamhost.com [69.163.242.240]

Trace complete.[/code]


#2

Is wget using HTTP on port 80 or a different port?


#3

wget accesses my local server through a different port (48420) because my ISP blocks port 80.


#4

Welcome to the wonderful world of rate differentials. My ISP gives me 10+ Mbps download speeds… and 1 Mbps upload if I’m lucky. Most ISPs do that.


#5

[quote=“bobocat, post:4, topic:57537”]Welcome to the wonderful world of rate differentials. My ISP gives me 10+ Mbps download speeds… and 1 Mbps upload if I’m lucky. Most ISPs do that.
[/quote]

But why the difference between initiating scp locally and wget remotely?

Also, I do tons of work for clients using many different hosting companies. I very regularly see and expect ~400-500Kbps uploads to those servers with larger files. Only with dreamhost do I see this huge hit.

Is there anything in my traceroute that indicates where the slowdown occurs?


#6

Ah, I read your post too quickly. It still may be at the ISP level, but if you are seeing it only with DH, then it’s probably something with DH.