Recommended Tests

hey guys,

i have the att elite dsl package. i've had it for about 2 months. first month everything was perfect. the past two weeks though i've been losing my connection constantly. every few minutes sometimes. its a real annoyance. i've called att and they say my signal strength is great and they went through a bunch of their so called diagnostic tests with me. everything seems to check out yet i still lose connection. on the modem the power, ethernet, and dsl lights are always good, but the internet light is the one that usual goes off.

any helps would be greatly appreciated.


modem is a motorola, the standard given by att.

yes i have power cycled and reset the modem many times. what is the node? could you be more specific about that? thanks.

no router, just the modem. the att service rep. said there have been no outages in my area that would cause my connection problems.

took the test. here's some of the information.

WEB100 Enabled Statistics:
Checking for Middleboxes . . . . . . . . . . . . . . . . . .  Done
checking for firewalls . . . . . . . . . . . . . . . . . . .  Done
running 10s outbound test (client-to-server [C2S]) . . . . . 512.0kB/s
running 10s inbound test (server-to-client [S2C]) . . . . . . 4.91Mb/s

   ------  Client System Details  ------
OS data: Name = Windows XP, Architecture = x86, Version = 5.1
Java data: Vendor = Sun Microsystems Inc., Version = 1.6.0_13

   ------  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 = 77.12 msec; the Packet size = 1408 Bytes; and
There were 5 packets retransmitted, 162 duplicate acks received, and 164 SACK blocks received
The connection was idle 0 seconds (0%) of the time
S2C throughput test: Packet queuing detected: 2.27%
This connection is receiver limited 14.46% of the time.
This connection is sender limited 48.20% of the time.
This connection is network limited 37.32% 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

Server 'ndt.anl.gov' is probably behind a firewall. [Connection to the ephemeral port failed]
Client is probably behind a firewall. [Connection to the ephemeral port failed]
Information: Network Middlebox is modifying MSS variable
Server IP addresses are preserved End-to-End
Information: Network Address Translation (NAT) box is modifying the Client's IP address
   Server says [XXXXXXXX] but Client says [192.168.1.64]




WEB100 Kernel Variables:
Client: localhost/127.0.0.1
CurMSS: 1408
X_Rcvbuf: 262142
X_Sndbuf: 262142
AckPktsIn: 2308
AckPktsOut: 0
BytesRetrans: 7040
CongAvoid: 0
CongestionOverCount: 0
CongestionSignals: 4
CountRTT: 2141
CurCwnd: 49280
CurRTO: 276
CurRwinRcvd: 65535
CurRwinSent: 5840
CurSsthresh: 35200
DSACKDups: 0
DataBytesIn: 0
DataBytesOut: 6264636
DataPktsIn: 0
DataPktsOut: 4432
DupAcksIn: 162
ECNEnabled: 0
FastRetran: 4
MaxCwnd: 97152
MaxMSS: 1408
MaxRTO: 312
MaxRTT: 120
MaxRwinRcvd: 65535
MaxRwinSent: 5840
MaxSsthresh: 45056
MinMSS: 1408
MinRTO: 228
MinRTT: 28
MinRwinRcvd: 65535
MinRwinSent: 5840
NagleEnabled: 1
OtherReductions: 2
PktsIn: 2308
PktsOut: 4432
PktsRetrans: 5
RcvWinScale: -1
SACKEnabled: 3
SACKsRcvd: 164
SendStall: 0
SlowStart: 0
SampleRTT: 80
SmoothedRTT: 76
SndWinScale: -1
SndLimTimeRwin: 1495849
SndLimTimeCwnd: 3856714
SndLimTimeSender: 4982688
SndLimTransRwin: 289
SndLimTransCwnd: 754
SndLimTransSender: 1034
SndLimBytesRwin: 1539032
SndLimBytesCwnd: 4352940
SndLimBytesSender: 372664
SubsequentTimeouts: 0
SumRTT: 165108
Timeouts: 0
TimestampsEnabled: 0
WinScaleRcvd: -1
WinScaleSent: -1
DupAcksOut: 0
StartTimeUsec: 946210
Duration: 10338818
c2sData: 2
c2sAck: 2
s2cData: 3
s2cAck: 3
half_duplex: 0
link: 0
congestion: 0
bad_cable: 0
mismatch: 0
spd: 4.85
bw: 4.64
loss: 0.000902527
avgrtt: 77.12
waitsec: 0.00
timesec: 10.00
order: 0.0702
rwintime: 0.1447
sendtime: 0.4821
cwndtime: 0.3732
rwin: 0.5000
swin: 2.0000
cwin: 0.7412
rttsec: 0.077117
Sndbuf: 262142
aspd: 0.00000
CWND-Limited: 683.90
minCWNDpeak: 2816
maxCWNDpeak: 97152
CWNDpeaks: 4

The theoretical network limit is 4.64 Mbps
The NDT server has a 127.0 KByte buffer which limits the throughput to 25.93 Mbps
Your PC/Workstation has a 63.0 KByte buffer which limits the throughput to 6.48 Mbps
The network based flow control limits the throughput to 9.61 Mbps

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




edit out personal info

yes, when i talked to the service rep he said the modem had to be two feet away from all electronics. i have since moved the modem and take the filter off this dsl line as there is no phone like on this line. but still the problem persists. that is interesting information though.

And there is also moving the modem to a different phone plug. Since sometimes one of the phone wire runs can be damaged or have a bad connection in either the phone plug outlet or at the side of the house(demarcation point) where all the wires come in.


I've got a Thomson Speed Touch DSL modem that is one inch from my router. 4 inches from one speaker and above a nightmare of wires under the desk. And a cordless phone about 12 inches away(combo 5.8GHz and 900MHz).

Not everything shows up to call support's online tool and a free tech visit is the best way to go.
 Sometimes they will switch out the modem too, just to be sure.  Occationally they may switch you to a different card at the Node(DSLaM). I think some people do have problems if they get a 'refurbished modem'. But there should be a sticker on the modem if that is the case.

Well like zalternate posted, it's difficult to diagnose every issue with the tools they have at the call center , and the tech would probably be the best idea right now.