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Network speed on MBP caped at 20Mbit.

JulianY

JulianY

macrumors newbie
Original poster
Jul 16, 2010
29
0
My network speed on my MBP is being caped at 20Mbit. This happens on both wifi and and wired. My isp provides 80Mb and other machines on the network can run speedtest.net test in excess of 70+

I have tried everything i can fin including disabling IPv6, open DNS, manual setting the MTU etc etc. but nothing seems to change it

I am using a WNDR3700 router. I have tried disabling n band and only running g , switching of 5Ghz , switching of 2.4ghz no change. however the fact that the choke is there also on the wired network leads me to believe its not this.

I have also tried taking the router out of the equation and connecting directly to the cable box. same thing 20Mb cap

i would be great-full for any suggestions

Julian
 
chachawpi thanks for the iperf tip, but i am now even more confused :confused:

on WIFI to windows server
Code: 
julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -c 192.168.2.10
------------------------------------------------------------
Client connecting to 192.168.2.10, TCP port 5001
TCP window size:  129 KByte (default)
------------------------------------------------------------
[  3] local 192.168.2.101 port 55533 connected with 192.168.2.10 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  94.6 MBytes  79.2 Mbits/sec

on cat5
Code: 
------------------------------------------------------------
Client connecting to 192.168.2.10, TCP port 5001
TCP window size:  129 KByte (default)
------------------------------------------------------------
[  3] local 192.168.2.104 port 55538 connected with 192.168.2.10 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   111 MBytes  92.8 Mbits/sec


However using the MBP as a server :confused:
on wifi
Code: 
 on wifi
julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 KByte (default)
------------------------------------------------------------
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1478
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  35.0 MBytes  29.4 Mbits/sec
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1479
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  41.4 MBytes  34.7 Mbits/sec
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1480
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  27.8 MBytes  23.3 Mbits/sec
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1481
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  39.3 MBytes  33.0 Mbits/sec
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1482
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  37.2 MBytes  31.2 Mbits/sec
[  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1483
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  32.3 MBytes  27.1 Mbits/sec

and on cat 5

Code: 
julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 KByte (default)
------------------------------------------------------------
[  4] local 192.168.2.106 port 5001 connected with 192.168.2.10 port 1505
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  67.7 MBytes  56.8 Mbits/sec
[  4] local 192.168.2.106 port 5001 connected with 192.168.2.10 port 1507
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  68.4 MBytes  57.3 Mbits/sec
but using speedtest.net

From my MBP


From my desktop


not sure how to interpret the results but it look to me like i have a choke on incoming data some how :mad:
 
no its set to 100 because i don't have a gig switch yet
 
I have a similar issue, though not identical. When accessing the internet over wireless, I can't get past 20mbps. To other machines on the same subnet, I can. Wired works fine.

Via ethernet:
MBP->speedtest.net: 60mbps down
G5 tower->speedtest.net: 60mbps down

Via 802.11N network
MBP->G5 (tower is wired): 90mbps down
MBP->speedtest.net: 20mbps
MBP->G5->speedtest.net (using ssh -D socks proxying through the G5 to get to speedtest.net): 60mbps down


As far as I can tell, OS X does something "different" with either individual packets or TCP connection options going to a remote network. Over wireless I can access other machines on the same network at near 100mbps. As soon as I hit something on the internet, 20mbps. It's interesting that we're seeing the same value.


I've spent hours troubleshooting this. I could not figure it out. Both my fall 2008 unibody and spring 2010 unibody exhibit the exact same behavior. I've looked at packet traces, connections both wired and wireless look identical: both have window scaling enabled set to the same values, and sack enabled.

I've tried playing with the following sysctl variables:
net.inet.tcp.slowstart_flightsize
net.inet.tcp.local_slowstart_flightsize
net.inet.tcp.recvspace

I've had no luck. If anyone has insight into this, please let me know!
The most telling thing is that a connection proxied through a machine on the same subnet works fine. That's the most bizarre part.
 
I consistently pull 55MB/s (440mbit) on mine, you have a network setup problem.
I also don't use wireless though, so..
 
RedReplicant said:
I consistently pull 55MB/s (440mbit) on mine, you have a network setup problem.
I also don't use wireless though, so..
Click to expand...

Are you replying to me or the OP? My machine works fine connected to gig ethernet - I did not test local transfer speeds over wired ethernet, what's the point? I know that works properly.

The OP only has a 100mbit switch, so obviously he's not going to get transfer rates of half a gig.
 
akramer said:
Are you replying to me or the OP? My machine works fine connected to gig ethernet - I did not test local transfer speeds over wired ethernet, what's the point? I know that works properly.

The OP only has a 100mbit switch, so obviously he's not going to get transfer rates of half a gig.
Click to expand...
I wasn't talking LAN transfers either.
 
akramer said:
This speedtest was done over wireless, not wired, right?
Can you try this with a cat5 cable plugged into your machine and airport disabled?
Click to expand...

yes on wifi , hear you go on cat5 as requested

 
OP consider yourself lucky

881864152.png

881868034.png
 
@akramer

The proxy thing, seems to confirm what i am seeing, the bandwidth loss is when you leave the LAN.

Out of interest what router are you using? I am just wondering about going down the apple store , telling them the story and getting an Airport Extreame to be returned if it does not fix the problem.

JY
 
JulianY said:
@akramer

The proxy thing, seems to confirm what i am seeing, the bandwidth loss is when you leave the LAN.

Out of interest what router are you using? I am just wondering about going down the apple store , telling them the story and getting an Airport Extreame to be returned if it does not fix the problem.

JY
Click to expand...

I have a Netgear WNR3500L running Tomato.
 
JulianY said:
I just wonder if osx detects netgear and dumbs down ?

sounds crazy, but i am struggling for another explanation

J
Click to expand...

My speeds from one machine to another over the same wireless router are fine, it's only when accessing the internet. I can't see how it could be related to the vendor of the wireless AP.

I think it might be related to interface speed - my WNR3500L has a gigabit switch, on which my MBP works fine. You're plugging into a 100mbit switch. I'll try wired at 100mbps later to see if I'm capped at 20mbps from the internet.
 
akramer said:
My speeds from one machine to another over the same wireless router are fine, it's only when accessing the internet. I can't see how it could be related to the vendor of the wireless AP.

I think it might be related to interface speed - my WNR3500L has a gigabit switch, on which my MBP works fine. You're plugging into a 100mbit switch. I'll try wired at 100mbps later to see if I'm capped at 20mbps from the internet.
Click to expand...

My router is gigabit, but my switch in this room is not.I have a replacement on order. My reasoning is every time i find some one with a similar problem statistically its a ne gear rooter.

I have tried connecting the MBP to the cable modem which is gigabit and that makes no difference, which I admit goes against the above

I am totally lost with this one

J
 
JulianY said:
I am totally lost with this one
Click to expand...

... You're not the only one.

I'm following this thread with intrigue but I'm curious if this bandwidth problem is just restricted to port 80 and would it also occur with Windows running under bootcamp? Not trying to say get Windows installed but if anyone else having similar problems and has already tested against this setup, a response would be nice. Just trying to establish whether its an OS or hardware issue. Saying that, lets see what happens when you get your switch changed.

Best of luck.
 
i'm using a netgear DG834G.
It'd be interesting to see if it was an issue with netgear as i am looking to upgrade soon to something with wireless N
 
Hm.

My download speeds are terrible so I ran this test. I have the 20 dollar cox plan which is 3mbs (horrible I know) and my speedtest is showing my download speed at 1mbps.

This normal?
 
I do see similar speeds, but I have a 22/1 connection so I guess I couldn't get any higher either way.



Try sticking a router between two of your computers to test the WAN theory.
 
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