Low Bandwidth/slow Speed: I Lodged This Complaint

kream

Newbie
[OP]
Oct 15, 2006
6
0
This is the complaint that I just mailed the nodal customer care officer for the NCR.
If anyone is experiencing this problem (low bandwidth combined with very fast
blinking of the data transfer lights on the "modem") can they confirm this problem exists?


Dear Mr. Sarma,

My name is Aniruddha Shankar and I am a DSL customer of Airtel with
phone number 4280xxxx. My customer ID is 11xxxxxx. I connect to the
Internet using a Beetel 220BX ADSL "modem", which I use in bridged
mode (PPP over Ethernet (PPPoE) ). My plan is the 256kilobit/sec
unlimited usage one, in which I pay a flat rate per month regardless
of data download or time spent online.

In the last month or so, I have been experiencing a strange problem.
My speed, which used to be very good sometimes drops drastically. When
this happens, my modem's data and pc/usb lights as well as the
computer's LAN card light start blinking together extremely fast. I
just checked my speed at your speed test in
http://speed.touchtelindia.net/meter.php and the speed given is 54.10
kilobit/sec.

I am a network engineer with 9 years of experience with TCP/IP
networks, specialising in LINUX/UNIX networks, and therefore I decided
to try and investigate this problem.

I decided to view and capture the data packets that were causing the
modem lights and my LAN card light to blink so fast. To use this I
used an industry-standard packet capture tool, Wireshark (formely
Ethereal). To summarise my findings, it seems that packets meant for
another IP address are wrongly being received by my machine. Of
course, I am not familiar with your internal network architecture, but
a possible cause for this might be a malfunctioning DSLAM that is
either not functioning in switched mode or is not isolating ports
properly. Technical details are appended. As you will appreciate, this
is a matter that cannot be resolved by call centre executives and I
would appreciate it if you would forward this matter to your network
operations engineers and put me in touch with them. I would be glad to
communicate with them on this matter and test any solutions that they
might have.

Best regards,
Aniruddha Shankar


TECHNICAL DETAILS
-------------------------------
I captured traffic for a mere 2.7 seconds, generating a 3MB capture
log file. This capture file is available at
http://191a.net/20061029.pcap . This file is in the standard
tcpdump/libpcap format and can be read by Wireshark, which is
available at http://www.wireshark.org/download.html . Despite
absolutely no network traffic from my end, packets were being received
at a rate of approximately 100 packets/sec. They seem to be packets
from a wide range of IP addresses that have the destination
203.101.7.61, which resolved to
dsl.delhi.061.7.101.203.touchtelindia.net. At this time, my own IP
address was 203.101.13.XXX. It might be significant that no packets
with the source 203.101.7.61 were seen during the time.
 

Karan

I am a n00b
Regulars
Aug 23, 2006
1,343
122
Gurgaon
Well its a common thing to have torrent client traffic coming in after ever after the person who was assigned the IP before. But i have never seen this happen. Odd indeed
 

max

Regulars
Regulars
Oct 6, 2005
2,766
6
u sure they are not just ARP, RARP packets? OR It may be likely that some switch has fallen back to the fail open mode. May be someone is flooding it with nonsense packets!
 


kream

Newbie
[OP]
Oct 15, 2006
6
0
QUOTE(Karan_S @ Oct 29 2006, 04:13 PM) [snapback]67104[/snapback]
Well its a common thing to have torrent client traffic coming in after ever after the person who was assigned the IP before. [/b]

Yes, that is not unknown - the traffic drops off after a while as the various peers mark this particular IP "dead". Regardless, this is not the case as the destination IP differs from mine!


QUOTE(max @ Oct 29 2006, 07:41 PM) [snapback]67122[/snapback]
u sure they are not just ARP, RARP packets? OR It may be likely that some switch has fallen back to the fail open mode. May be someone is flooding it with nonsense packets!
[/b]

Absolutely sure they are not ARP / RARP packets. Take a look at the pcap file in ethereal/wireshark or any other pcap-capable network monitor and see. I think you're right in that the switch has stopped isolating ports. Bummer. Hope the airtel nodal customer care guy does not brush me off.
 

max

Regulars
Regulars
Oct 6, 2005
2,766
6
Kream, i guess they'll listen to you but dont keep too many hopes from them :p
 

kream

Newbie
[OP]
Oct 15, 2006
6
0
Some progress at least. They promise 48 hour redressal of problem. I got my first call from airtel about 60 hours after I sent the email. I then spoke to someone from the NOC who said someone would get in touch with me and fix up an appointment to come to my house to inspect my connection. The first person i talked to agreed with me when I said that I should give them a complete packet capture, which I just emailed. aage aage dekhte hain kya kya hota hai... will keep this post posted.cheersKream
 


netant

۩ ŚŧäГЏЅ ΞПЖ
Regulars
Apr 23, 2006
845
15
Somewhere
QUOTE(Kream @ Nov 3 2006, 02:15 AM) [snapback]67563[/snapback]
Some progress at least. They promise 48 hour redressal of problem. I got my first call from airtel about 60 hours after I sent the email. I then spoke to someone from the NOC who said someone would get in touch with me and fix up an appointment to come to my house to inspect my connection. The first person i talked to agreed with me when I said that I should give them a complete packet capture, which I just emailed. aage aage dekhte hain kya kya hota hai... will keep this post posted.
cheers
Kream
[/b]

my best wishes r with u.......