Looking for help optimizing connection

[Zucharn]

Browser/OS = Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1
TCP options string = 020405b40103030301010402
MTU = 1500
MTU is fully optimized for broadband.
MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.
Default TCP Receive Window (RWIN) = 512000
RWIN Scaling (RFC1323) = 3 bits (scale factor of 6)
Unscaled TCP Receive Window = 64000

For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)
bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 20480 kbps (2560 KBytes/s) @ 200ms
Your TCP Window limits you to: 8192 kbps (1024 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 56 hops

TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00000000 (0)

I am running windows XP pro, and my ISP is cablevision Optimum online. My connection runs through a cable modem and a router.

speed test results from speakeasy new york
Download Speed: 1541 kbps (192.6 KB/sec transfer rate)
Upload Speed: 787 kbps (98.4 KB/sec transfer rate)

second run of tests a few minutes later
Download Speed: 5502 kbps (687.8 KB/sec transfer rate)
Upload Speed: 866 kbps (108.3 KB/sec transfer rate)

my main problem at the moment is getting very slow connection speeds on average, sometimes they peak, and in Battlefield 2 I suffer from frequent "there is a problem with your connection" messages, even when I have a low ping.

[Philip]

You can try using the TCP Optimizer, just apply the optimal settings... But your problems are probably signal related. What cable modem are you running ? It might be able to display the signal levels, or you might need for a tech to look at it.

[Zucharn]

I'm running a scientific atlanta WebSTAR DPC2100,
Receive Power Level
0.1 dBmV

Transmit Power Level
46.5 dBmV
last time a tech checked, everything was fine.

I ran tcp optimizer, set it to 6mbps, I think the slow dl is due to load on my node, but I don't know about the disconnections.

[Philip]

Signal levels look fine, could be just congestion on your node. Does it significantly slow down at peak times, or is it random ?

You might want to do some traceroutes, and see how many hops away from you the latency jumps much higher, it might give you some idea.

[trogers]

In some cases that I have come across, wide fluctuations in speed within minutes means there is a strong source of electromagnetic interference affecting signal cables or devices (modem/router).

Here is an interesting case:

http://www.testmy.net/forum/t-11588

[Philip]

Very good point trogers.

Here is another interesting one: http://www.speedguide.net/read_articles.php?id=1885

[Zucharn]

I read about that on these forums, there is a bit of a rats nest of cables, but the devices themselves are separated by about 3'. it does slow down at peak times, but it also drops randomly, for example at 3am it dropped to about 56k. I also seem to get bursts of packet loss, where my connection will be fine for hours, and then I start to get these interruptions every few minutes. Just remembered. there is one splitter before the cable modem, and the modem hooks into my router. the router is connected to my mom's computer and a hub which is then connected to my computer and my brother's as my computer couldn't deal with the signal strength lost on a 50' cable. the hub is a 10mbps 4 port hub. could this be causing packet loss?

[trogers]

Do this network diagnostic test and post all results including the 'Statistics' and 'More Details' buttons below the test box:

http://nitro.ucsc.edu/

[mccoffee]

I read about that on these forums, there is a bit of a rats nest of cables, but the devices themselves are separated by about 3'. it does slow down at peak times, but it also drops randomly, for example at 3am it dropped to about 56k. I also seem to get bursts of packet loss, where my connection will be fine for hours, and then I start to get these interruptions every few minutes. Just remembered. there is one splitter before the cable modem, and the modem hooks into my router. the router is connected to my mom's computer and a hub which is then connected to my computer and my brother's as my computer couldn't deal with the signal strength lost on a 50' cable. the hub is a 10mbps 4 port hub. could this be causing packet loss?


You are better off using a swtich instead of a hub since a swtich would break up collisons right now you got a brodacast doman going on meaing the hub will forward data to all the ports except the uplink one.

[Zucharn]

to mrcoffee, the problems happen even when my computer is the only one turned on, so I don't believe it has to do with collisions.

TCP/Web100 Network Diagnostic Tool v5.3.3d
click START to begin
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 1.03Mb/s
running 10s inbound test (server to client) . . . . . . 1.50Mb/s
Your PC is connected to a Cable/DSL modem

click START to re-test

WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 1.03Mb/s
running 10s inbound test (server to client) . . . . . . 1.50Mb/s

------ Client System Details ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.5.0_04

------ Web100 Detailed Analysis ------
Cable modem/DSL/T1 link found.
Link set to Full Duplex mode
No network congestion discovered.
Good network cable(s) found
Normal duplex operation found.

Web100 reports the Round trip time = 213.7 msec; the Packet size = 1460 Bytes; and
There were 89 packets retransmitted, 162 duplicate acks received, and 180 SACK blocks received
The connection was idle 0 seconds (0%) of the time
This connection is receiver limited 64.3% of the time.
This connection is network limited 35.67% of the time.

Web100 reports TCP negotiated the optional Performance Settings to:
RFC 2018 Selective Acknowledgment: ON
RFC 896 Nagle Algorithm: ON
RFC 3168 Explicit Congestion Notification: OFF
RFC 1323 Time Stamping: OFF
RFC 1323 Window Scaling: ON
Packet size is preserved End-to-End
Server IP addresses are preserved End-to-End
Information: Network Address Translation (NAT) box is modifying the Client's IP address
Server says [xx.xx.xx.xx] but Client says [xxx.xxx.x.xx]

WEB100 Kernel Variables:
Client: localhost/127.0.0.1
AckPktsIn: 626
AckPktsOut: 0
BytesRetrans: 129940
CongAvoid: 72
CongestionOverCount: 0
CongestionSignals: 1
CountRTT: 435
CurCwnd: 129940
CurMSS: 1460
CurRTO: 390
CurRwinRcvd: 256960
CurRwinSent: 16304
CurSsthresh: 128480
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 1995300
DataPktsIn: 0
DataPktsOut: 1367
DupAcksIn: 162
ECNEnabled: 0
FastRetran: 1
MaxCwnd: 258420
MaxMSS: 1460
MaxRTO: 920
MaxRTT: 460
MaxRwinRcvd: 256960
MaxRwinSent: 16304
MaxSsthresh: 128480
MinMSS: 1460
MinRTO: 300
MinRTT: 100
MinRwinRcvd: 64240
MinRwinSent: 16304
NagleEnabled: 1
OtherReductions: 0
PktsIn: 628
PktsOut: 1367
PktsRetrans: 89
X_Rcvbuf: 103424
RcvWinScale: 7
SACKEnabled: 3
SACKsRcvd: 180
SendStall: 0
SlowStart: 263
SampleRTT: 130
SmoothedRTT: 150
X_Sndbuf: 103424
SndWinScale: 2
SndLimTimeRwin: 6438218
SndLimTimeCwnd: 3571143
SndLimTimeSender: 3257
SndLimTransRwin: 3
SndLimTransCwnd: 2
SndLimTransSender: 3
SndLimBytesRwin: 346020
SndLimBytesCwnd: 1493580
SndLimBytesSender: 155700
SubsequentTimeouts: 0
SumRTT: 92960
Timeouts: 0
TimestampsEnabled: 0
WinScaleRcvd: 2
WinScaleSent: 7
DupAcksOut: 0
StartTimeUsec: 672182
Duration: 10013033
c2sData: 2
c2sAck: 2
s2cData: 9
s2cAck: 3
half_duplex: 0
link: 100
congestion: 0
bad_cable: 0
mismatch: 0
spd: 0.00
bw: 1.93
loss: 0.000731529
avgrtt: 213.70
waitsec: 0.00
timesec: 10.00
order: 0.2588
rwintime: 0.6430
sendtime: 0.0003
cwndtime: 0.3567
rwin: 1.9604
swin: 64.0000
cwin: 1.9716
rttsec: 0.213701
Sndbuf: 8388608
aspd: 1.63118

Checking for mismatch on uplink
(speed > 50 [0>50], (xmitspeed < 5) [1.03<5]
(rwintime > .9) [0.64>.9], (loss < .01) [7.31<.01]
Checking for excessive errors condition
(loss/sec > .15) [7.31>.15], (cwndtime > .6) [0.35>.6],
(loss < .01) [7.31<.01], (MaxSsthresh > 0) [128480>0]
Checking for 10 Mbps link
(speed < 9.5) [0<9.5], (speed > 3.0) [0>3.0]
(xmitspeed < 9.5) [1.03<9.5] (loss < .01) [7.31<.01], (mylink > 0) [3.0>0]
Checking for Wireless link
(sendtime = 0) [3.0E=0], (speed < 5) [0<5]
(Estimate > 50 [1.93>50], (Rwintime > 90) [0.64>.90]
(RwinTrans/CwndTrans = 1) [3/2=1], (mylink > 0) [3.0>0]
Checking for DSL/Cable Modem link
(speed < 2) [0<2], (SndLimTransSender = 0) [3=0]
(SendTime = 0) [3.0E-4=0], (mylink > 0) [3.0>0]
Checking for half-duplex condition
(rwintime > .95) [0.64>.95], (RwinTrans/sec > 30) [0.3>30],
(SenderTrans/sec > 30) [0.3>30], OR (mylink <= 10) [3.0<=10]
Checking for congestion
(cwndtime > .02) [0.35>.02], (mismatch = 0) [0=0]
(MaxSsthresh > 0) [128480>0]

estimate = 1.93 based on packet size = 11Kbits, RTT = 213.7msec, and loss = 7.31529E-4
The theoretical network limit is 1.93 Mbps
The NDT server has a 8192.0 KByte buffer which limits the throughput to 299.48 Mbps
Your PC/Workstation has a 250.0 KByte buffer which limits the throughput to 9.17 Mbps
The network based flow control limits the throughput to 9.22 Mbps

Client Data reports link is 'T1', Client Acks report link is 'T1'
Server Data reports link is '10 Gig', Server Acks report link is 'Ethernet'

this test was run at off peak times

[mccoffee]

I"m just stating that you would be better off with the switch. So if I"m understanding you right if the computer is right diectly to the modem it still happens??


I would try this leave modem off for 5 mins then router off for 2 then hub

Turn modem back on wailt a few seconds then router then hub.


What router do you own model and make of it? Check for new firmware also enable icmp if it's disabled on the router.

[trogers]

"This connection is receiver limited 64.3% of the time.
This connection is network limited 35.67% of the time.

Your PC/Workstation has a 250.0 KByte buffer which limits the throughput to 9.17 Mbps. The network based flow control limits the throughput to 9.22 Mbps"

Mccoffee is right. Your problem does not lie in RWIN (buffer) setting but in your LAN setup. Smooth signal transmission is 64% limited by your setup.

Once you have resolved your LAN setting, you may look into reducing your RWIN (buffer) to 124 Kbytes to suit a bandwidth of 5 Mbps.

[Zucharn]

there is no new firmware for my router, and I'm not sure wether it still has problems connected directly to the modem, I don't have a cable long enough

ran test again
Web100 reports the Round trip time = 184.04 msec; the Packet size = 1460 Bytes; and
There were 16 packets retransmitted, 68 duplicate acks received, and 76 SACK blocks received
The connection was idle 0 seconds (0%) of the time
This connection is network limited 99.97% of the time.
Excessive packet loss is impacting your performance, check the auto-negotiate function on your local PC and network switch
I have no idea how to fix it.

[Zucharn]

posting instead of editing because It's been a few days, and I need help troubleshooting my network. I reran the test and it keeps saying
This connection is network limited 99.97% of the time.

[trogers]

When the nitro test says your connection is network limited 99.97% and made no mention of receiver limited, it means no further problems have been detected in your LAN setup. "Network limited" usually just means your signal experienced rather heavy internet traffic and your optimum speed cannot be achieved.

Try to do some speedtests during low traffic period perhaps during 3-6 am to see if your comp setting is okay.

[Zucharn]

at about 4 am I get 6mb dl speed, is there anything I can do about the packet loss and high pings at peak hours? maybe my isp just oversold the node or something

[mccoffee]

http://www.pcpitstop.com/internet/tracert.asp

[Zucharn]

1 1 x.x.x.x
2 33 10.86.160.1
3 20 67.83.242.162 (dstswr2-vlan2.rh.brfdnj.cv.net)
4 20 67.83.242.133 (r4-ge10-2.mhe.prnynj.cv.net)
5 27 65.19.112.130 (r2-srp3-0.wan.prnynj.cv.net)
6 26 65.19.96.195 (451be0c3.cst.lightpath.net)
7 35 65.19.97.226 (r1-pos3-0.in.asbnva16.cv.net)
8 * 100 0.0.0.0
9 43 66.192.255.228 (core-01-so-0-1-0-0.asbn.twtelecom.net)
10 71 66.192.255.21 (core-02-so-0-0-0-0.dlfw.twtelecom.net)
11 57 66.192.253.125 (hagg-02-ge-3-3-0-504.dlfw.twtelecom.net)
12 53 168.215.241.134
13 61 64.29.192.225 (daa.g921.disb.datareturn.com)
14 63 64.29.192.234 (daa.g920.disa.datareturn.com)
15 61 64.29.192.213 (daa.g906.p40a.datareturn.com)
16 52 64.29.201.21 (pcpitstop.com)

[mccoffee]

8 * 100 0.0.0.0

this makes me wonder

[Zucharn]

couldn't it have just rejected the ping?
however, this worries me.
1 1 x.x.x.x
2 175 10.86.160.1
3 17 67.83.242.162 (dstswr2-vlan2.rh.brfdnj.cv.net)
4 20 67.83.242.133 (r4-ge10-2.mhe.prnynj.cv.net)
5 18 65.19.112.129 (r1-srp3-0.wan.prnynj.cv.net)
6 23 65.19.96.211 (451be0d3.cst.lightpath.net)
7 37 167.206.8.150 (r1-pos1-0.in.asbnva16.cv.net)
8 * 100 0.0.0.0
9 52 63.217.30.70 (www.speedguide.net)

[mccoffee]

2 175 that spiked hard hmmm well it's on ur providers end not sure what to tell ya

[Zucharn]

pinged my default gateway, got the ip from my router status page, it averages 30ms, but spikes up to 700ms. I'm guessing that's a bad thing. I also get about 1% packet loss off it.