So a few weeks ago I was experiencing intermittent signals to my modem. After lengthy conversations with Comcast it was determined the was significant packet loss and a tech was sent to my house. He tested the signals outside and inside and said that they were all within "acceptable" range which usually means it could be better, but they do not want to take the time to make it better. Two weeks pass, and I have gone from intermittent signals @ 6.2 Mbps down to intermittent signals @ anywhere from .27Mbps to .34 Mbps down. A lengthy conversation with comcast today resulted in yet another service call. I always check my speeds on this site and have just recently started reading the posts and thread herein. After attempting to troubleshoot and repair this problem myself through cablenut and TCPOptimized, I registered and I am bringing my problems to the boards. Any and all help is greatly appreciated.
I am running Win/XP SP2, have tweaked with cablenut and TCPOptimizer, have run CCleaner, once a week I run spybot s&d, spywareblaster and all updated anitvirus and windows updates. There is definitely no malware spyware or virii on my computer. It seems to be either a cabling issue inside the house or from the pole to the junction box outside. Anyways, here is the results from all tests that I have run and it seems latency/packet loss is my biggest issue. Weird thing is, upstream is now faster than downstream. I suscribe to Comcast 6000/384 and I usually get 6200/380ish and have never had problems like I have recently.
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) = 513920
RWIN Scaling (RFC1323) = 3 bits (scale factor of 6)
Unscaled TCP Receive Window = 64240
RWIN is a multiple of MSS
Other RWIN values that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of <-- current value
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: 20556.8 kbps (2569.6 KBytes/s) @ 200ms
Your TCP Window limits you to: 8222.72 kbps (1027.84 KBytes/s) @ 500ms
MTU Discovery (RFC1191) = ON
Time to live left = 54 hops
TTL value is ok.
Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON
IP type of service field (RFC1349) = 00100000 (32)
Precedence (priority) = 001 (priority)
Delay = 0 (normal delay)
Throughput = 0 (normal throughput)
Reliability = 0 (normal reliability)
Cost = 0 (normal cost)
Check bit = 0 (correct, 8th checking bit must be zero)
DiffServ (RFC 2474) = CS1 001000 ( - class 1 (RFC 2474). Similar forwarding behavior to the ToS Precedence field.
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The current date is: Sat 09/16/2006
The current time is: 21:59:40.32
Microsoft Windows XP [Version 5.1.2600]
Pinging testmy.net [67.18.179.85] with 32 bytes of data:
Request timed out.
Reply from 67.18.179.85: bytes=32 time=31ms TTL=53
Reply from 67.18.179.85: bytes=32 time=52ms TTL=53
Reply from 67.18.179.85: bytes=32 time=49ms TTL=53
Reply from 67.18.179.85: bytes=32 time=58ms TTL=53
Reply from 67.18.179.85: bytes=32 time=53ms TTL=53
Reply from 67.18.179.85: bytes=32 time=53ms TTL=53
Reply from 67.18.179.85: bytes=32 time=49ms TTL=53
Reply from 67.18.179.85: bytes=32 time=48ms TTL=53
Reply from 67.18.179.85: bytes=32 time=50ms TTL=53
Reply from 67.18.179.85: bytes=32 time=55ms TTL=53
Reply from 67.18.179.85: bytes=32 time=49ms TTL=53
Ping statistics for 67.18.179.85:
Packets: Sent = 12, Received = 11, Lost = 1 (8% loss),
Approximate round trip times in milli-seconds:
Minimum = 31ms, Maximum = 58ms, Average = 49ms
Ping Complete.
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Tracing route to testmy.net [67.18.179.85]
over a maximum of 30 hops:
1 10 ms 9 ms 11 ms xx.xx.xx.x
2 28 ms 29 ms * s01b1.bartlett.ga.savannah.comcast.net [xx.xx.xxx.xx]
3 9 ms 8 ms 10 ms s01g1.savannah.ga.savannah.comcast.net [xx.xx.xxx.xx]
4 36 ms 36 ms * 12.124.64.25
5 * 55 ms 57 ms tbr2-p013801.attga.ip.att.net [12.123.20.174]
6 51 ms * * tbr1-cl13.dlstx.ip.att.net [12.122.2.89]
7 46 ms 36 ms 37 ms gar1-p340.dlrtx.ip.att.net [12.123.16.161]
8 41 ms 32 ms 32 ms 12.119.136.14
9 * * 51 ms vl32.dsr01.dllstx3.theplanet.com [70.85.127.61]
10 50 ms 53 ms 49 ms vl42.dsr02.dllstx4.theplanet.com [70.85.127.91]
11 56 ms * 59 ms gi1-0-1.car17.dllstx4.theplanet.com [67.18.116.69]
12 48 ms 55 ms 51 ms 55.b3.1243.static.theplanet.com [67.18.179.85]
Trace complete.
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:::.. testmy.net test results ..:::
Download Connection is:: 264 Kbps about 0.26 Mbps (tested with 386 kB)
Download Speed is:: 32 kB/s
Upload Connection is:: 379 Kbps about 0.38 Mbps (tested with 748 kB)
Upload Speed is:: 46 kB/s
Tested From:: https://testmy.net (Server 1)
Test Time:: 2006/09/16 - 7:05pm
D-Validation Link:: https://testmy.net/stats/id-FYD5J86IT
U-Validation Link:: https://testmy.net/stats/id-1UTGVC453
User Agent:: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7 [!]
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WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done
running 10s outbound test (client to server) . . . . . 399.49Kb/s
running 10s inbound test (server to client) . . . . . . 120.72kb/s
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------ Client System Details ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.5.0_06
------ Web100 Detailed Analysis ------
Cable modem/DSL/T1 link found.
Link set to Full Duplex mode
Information: throughput is limited by other network traffic.
Good network cable(s) found
Normal duplex operation found.
Web100 reports the Round trip time = 179.19 msec; the Packet size = 1460 Bytes; and
There were 17 packets retransmitted, 20 duplicate acks received, and 22 SACK blocks received
The connection stalled 2 times due to packet loss
The connection was idle 0.86 seconds (8.6%) of the time
This connection is network limited 99.96% of the time.
Excessive packet loss is impacting your performance, check the auto-negotiate function on your local PC and network switch
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.xxx] but Client says [192.168.1.101]
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WEB100 Kernel Variables:
Client: localhost/127.0.0.1
AckPktsIn: 72
AckPktsOut: 0
BytesRetrans: 24820
CongAvoid: 28
CongestionOverCount: 0
CongestionSignals: 9
CountRTT: 37
CurCwnd: 5840
CurMSS: 1460
CurRTO: 430
CurRwinRcvd: 513920
CurRwinSent: 16304
CurSsthresh: 2920
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 185420
DataPktsIn: 0
DataPktsOut: 127
DupAcksIn: 20
ECNEnabled: 0
FastRetran: 6
MaxCwnd: 7300
MaxMSS: 1460
MaxRTO: 540
MaxRTT: 300
MaxRwinRcvd: 513920
MaxRwinSent: 16304
MaxSsthresh: 2920
MinMSS: 1460
MinRTO: 330
MinRTT: 110
MinRwinRcvd: 64240
MinRwinSent: 16304
NagleEnabled: 1
OtherReductions: 0
PktsIn: 72
PktsOut: 127
PktsRetrans: 17
X_Rcvbuf: 103424
RcvWinScale: 7
SACKEnabled: 3
SACKsRcvd: 22
SendStall: 0
SlowStart: 13
SampleRTT: 110
SmoothedRTT: 170
X_Sndbuf: 103424
SndWinScale: 3
SndLimTimeRwin: 0
SndLimTimeCwnd: 10564644
SndLimTimeSender: 4256
SndLimTransRwin: 0
SndLimTransCwnd: 1
SndLimTransSender: 1
SndLimBytesRwin: 0
SndLimBytesCwnd: 185420
SndLimBytesSender: 0
SubsequentTimeouts: 1
SumRTT: 6630
Timeouts: 2
TimestampsEnabled: 0
WinScaleRcvd: 3
WinScaleSent: 7
DupAcksOut: 0
StartTimeUsec: 792956
Duration: 10575031
c2sData: 2
c2sAck: 2
s2cData: 9
s2cAck: 2
half_duplex: 0
link: 100
congestion: 1
bad_cable: 0
mismatch: 0
spd: 0.00
bw: 0.23
loss: 0.070866142
avgrtt: 179.19
waitsec: 0.86
timesec: 10.00
order: 0.2778
rwintime: 0.0000
sendtime: 0.0004
cwndtime: 0.9996
rwin: 3.9209
swin: 64.0000
cwin: 0.0557
rttsec: 0.179189
Sndbuf: 8388608
aspd: 0.46080
Checking for mismatch on uplink
(speed > 50 [0>50], (xmitspeed < 5) [0.39<5]
(rwintime > .9) [0>.9], (loss < .01) [0.07<.01]
Checking for excessive errors condition
(loss/sec > .15) [0.00>.15], (cwndtime > .6) [0.99>.6],
(loss < .01) [0.07<.01], (MaxSsthresh > 0) [2920>0]
Checking for 10 Mbps link
(speed < 9.5) [0<9.5], (speed > 3.0) [0>3.0]
(xmitspeed < 9.5) [0.39<9.5] (loss < .01) [0.07<.01], (mylink > 0) [3.0>0]
Checking for Wireless link
(sendtime = 0) [4.0E=0], (speed < 5) [0<5]
(Estimate > 50 [0.23>50], (Rwintime > 90) [0>.90]
(RwinTrans/CwndTrans = 1) [0/1=1], (mylink > 0) [3.0>0]
Checking for DSL/Cable Modem link
(speed < 2) [0<2], (SndLimTransSender = 0) [1=0]
(SendTime = 0) [4.0E-4=0], (mylink > 0) [3.0>0]
Checking for half-duplex condition
(rwintime > .95) [0>.95], (RwinTrans/sec > 30) [0>30],
(SenderTrans/sec > 30) [0.1>30], OR (mylink <= 10) [3.0<=10]
Checking for congestion
(cwndtime > .02) [0.99>.02], (mismatch = 0) [0=0]
(MaxSsthresh > 0) [2920>0]
estimate = 0.23 based on packet size = 11Kbits, RTT = 179.19msec, and loss = 0.070866142
The theoretical network limit is 0.23 Mbps
The NDT server has a 8192.0 KByte buffer which limits the throughput to 357.16 Mbps
Your PC/Workstation has a 501.0 KByte buffer which limits the throughput to 21.88 Mbps
The network based flow control limits the throughput to 0.31 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 'T1'
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Some earlier latency tests through the newest TCPOptimizer program were reporting packet losses ranging from 3% up to 40%. Any suggestions why I am having such inconsistent packet loss and low downstream speeds? It seems that upstream is unaffected. Thank you in advance for any and all help.