Gentoo Archives: gentoo-user

From: Harry Putnam <reader@×××××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] Re: [OT] etho app rating 10/100 etc in megabytes
Date: Thu, 24 Feb 2011 17:20:10
Message-Id: 871v2xgy0l.fsf@newsguy.com
In Reply to: [gentoo-user] Re: [OT] etho app rating 10/100 etc in megabytes by James
1 James <wireless@×××××××××××.com> writes:
2
3 > Harry Putnam <reader <at> newsguy.com> writes:
4 >
5 >
6 >
7 >> But still, when I'm trying to measure how much data is moving
8 >
9 > emerge bwmon,
10 >
11 > It measures across the ethernet ports, so adjust your test,
12 > according to what you want to measure, crossing the ethernet
13 > port on the target system.
14
15 First off.. thanks for the tips and help.
16
17 All I get from bwmon is a large mess of incomprehensible data ending in
18
19 ,----
20 | b7841000-b7881000 r-xp 00000000 03:05 6663 /lib/libncurses.so.5.7
21 | [...]
22 | b789e000-b78ba000 r-xp 00000000 03:05 7228 /lib/ld-2.12.2.so
23 | b78ba000-b78bb000 r-xp 00000000 00:00 0 [vdso]
24 | b78bb000-b78bc000 r--p 0001c000 03:05 7228 /lib/ld-2.12.2.so
25 | b78bc000-b78bd000 rw-p 0001d000 03:05 7228 /lib/ld-2.12.2.so
26 | bffae000-bffc4000 rw-p 00000000 00:00 0 [stack]
27 | Aborted
28 `----
29
30 And it has no man page whatsoever.
31
32 (it has a little help at bwmon -h)
33
34 But I recall using bwmon years ago so not sure whats happening that it
35 crashes for me.
36
37 >> and it seems quite slow for what is supposed to be a gigabyte network.
38 >
39 > Gigabit ethernet rarely runs full out constantly, something, (ram, cpu,
40 > interface, swith-latency....) mucks things up. Do not let your "copper"
41 > get to long either!
42
43 But that figures out to about 3-4 MB per second (assuming I did the
44 math right)
45
46 I said it was averaging about 230-237 MBytes per MINUTE , so giving it
47 a nice round 240 MB per MINUTE:
48
49 240 / 60 = 4MB per second... and that figures out to:
50
51 ( using this forumula: 1MBytes ps = 8000000 bits ps or 8 Mbits ps)
52
53 4 * 8000000 = 32 Mbits ps
54
55 That is not counting packets going the other way of course, but isn't
56 an incoming speed of 32Mega bits per second what one might expect from
57 adapters capable of 100 mbps... (not gigabit (1000))
58
59
60 What you've shown below appears to show gigabit network between h4 and
61 h5. Is that really to be expected?
62
63 >> gigabyte switch
64 >> | |
65 >> | |
66 >> (192.168.0.9) h4 h5 (192.168.0.17)
67
68 If you show the top half of the diagram you snipped, you see that h4
69 h5 are aimed at a switch/router/firewall above, that is only 100mbps.
70 The gigaswitch has no address, so I'm wondering if traffic between h4
71 and h5 has to go up thru the 100Mbps router to communicate with each
72 other.
73
74 I realized when I made the diagram that I was probably looking for
75 gigabit speeds where really only 100mbps was possible.
76
77 Take another look at the diagram (Knowing that h4 and h5 have there
78 default routes set to the netgear (100mbps) router.
79
80 Would it still be possible that h4 and h5 would communicate direct
81 thru the gigabit switch or would that traffic have to go up thru the
82 100 Mbps router above?
83
84 (Note that in the previous diagram I had mislabled (just a typo) the
85 gigabit switch as gigabyte switch)
86
87 internet
88 |
89 |
90 |
91 (netgear router is lan `default route' <= 10/100*****
92 NETGEAR ROUTER (inside address 192.168.0.20)
93 | | |
94 | | |
95 (192.168.0.5) h1 | h3 (192.168.0.7)
96 |
97 |
98 gigabit switch
99 | |
100 | |
101 (192.168.0.9) h4 h5 (192.168.0.17)
102
103
104 >> But also if I should be expecting h4 h5 to be able to use GigaByte
105 >> transfer speeds.
106 >
107 > Some fraction say 50% is good, if it is copper, unless the systems
108 > are smoking "gaming" systems or of very high quality resources.
109
110 I keep having a sneaking feeling I'm making some horrible mistake in
111 the math, but wouldn't the speeds I posted (240 MegaBytes per min)
112 figure out to something like 3.2+ % of the rated 1000 Mbits.
113
114 (I really hope I haven't demonstrated idiocy levels of math)