Slow throughput on 7.1 Mb/s line

Question

I ran some speed tests today to check my 7.1 Mb/s line as I do occasionally and I found out that even though I was syncing with the CO at 7661 my download speed tests are only coming back in the 1.1 to 2.0 range. Some were actually well below 1.0 today. Previously I was routinely getting speed tests in the 6.5 to 6.6 range on this line, which has been provisioned at this speed for 3 and a half years. My current transceiver stats are as follows:
Transceiver Statistics
Transceiver Revision: 7.2.3.0
Vendor ID Code: 4
Line Mode: ADSL2+ Mode
Data Path: Interleaved
Transceiver Information Downstream Path Upstream Path
DSL Speed (Kbits/Sec) 7661 863
Margin (dB) 6.0 14.0
Line Attenuation (dB) 45.0 25.0
Transmit Power (dBm) 19.4 12.1
I know that my downstream margin is low at 6.0 but this is a VERY STABLE line that will go weeks without losing sync even with that low margin. The ADSL2+ is really giving me some help at my attenuation.
So far today for troubleshooting I tried replacing my 7-year-old Westell 327W B90 modem with a brand-new Westell 327W D90 modem that I had stored away in a box. There was no difference in the speed tests when I used either modem. They were both running the 4.04.03 firmware which is the latest for the Westell 327W modems.
I also tried uninstalling and reinstalling my NIC card as I'm connected via ethernet cable to my modem. That made no difference in my speed tests either.
I did run a Network Diagnostic Tool at M-Lab with the following results:
Upload speed
0.73 Mb/s
Download speed
1.1 Mb/s
Network latency: 5.8e+2 msec round trip time
Jitter: 8.1e+2 msec
Your system: Windows XP version 5.1
Java version: 1.7.0_04 (x86)
TCP receive window: 255552 current, 255552 maximum
9.62464E-4 packets lost during test
Round trip time: 70 msec (minimum), 875 msec (maximum), 580.12 msec (average)
Jitter: 805 msec
0 seconds spend waiting following a timeout
TCP time-out counter: 935
130 selective acknowledgement packets received
No duplex mismatch condition was detected.
The test did not detect a cable fault.
Network congestion may be limiting the connection.
No network address translation appliance was detected.
0.9756% of the time was not spent in a receiver limited or sender limited state.
0.0% of the time the connection is limited by the client machine's receive buffer.
Optimal receive buffer: 261685248 bytes
0 duplicate ACKs set
So it looks like I have a network congestion issue going on. I'm wondering if it has to do with the router that I'm on or if my local CO (Fall River, MA) is having a more widespread problem. I'm thinking of keeping an eye on it for the next few days and see if it gets back to normal on its own. I'm very hesitant to contact Verizon as the last time I did a few years ago they cut my speed down to 5 from 7.1 and took away my ADSL2+. I had to talk to executive customer relations to get them back and it was not an easy task!
Does anyone have any suggestions or opinions about my situation?

Answer 1

PROBLEM RESOLVED
I contacted the Verizon Direct Forum at DSL Reports and received a telephone call from someone at the executive customer relations department at Verizon. He was able to have someone from my local Central Office who does network management/DSL provisioning contact me directly by phone. I was changed over to a "less congested" router right while I was on the phone with this person from my local CO. My ADSL2+ and 7.1 speed package were left intact on my line during the change to a new router. All seems to be well as I am now getting actual speed throughput of 6.5 to 6.6 even during peak evening hours!