[Chilli] Incorrectly high data usage over a short period of time

Mon Nov 9 15:01:12 UTC 2009

Dear Coova Chilli Community

Firstly, my setup:

   1. Coova Chilli 1.013
   2. Freeradius 2.1.5

I am absolutely perplexed by this bug. Not only that, but I cannot think of
any ways of reproducing it, so I am hoping someone in the community has come
accross this before. My problem is my NAS is reporting incorrectly high
usage over a short space of time. Where we are based (South Africa), the
fastest one's ADSL line speed can be is 4 mega bits per second. This
translates to about 0.47 megabytes per seconds, and that is if you are
lucky. We have three such lines multiplexed together, which means we can get
a throughput of about 0.47*3 = 1.41 megabytes per second. Unfortunately, we
have received a complaint claiming that chilli has deducted more than what
was used. Looking at the radius logs, I can ascertain that this is true.

Here is the initial start packet sent by chilli to radius (I have removed
username and Nas Identifier to protect privacy):

*Tue Oct 27 09:12:57 2009
        ChilliSpot-Version = "1.0.13"
        Acct-Status-Type = Start
        Calling-Station-Id = "00-1F-33-FF-BD-00"
        NAS-Port-Type = Wireless-802.11
        NAS-Port = 4
        NAS-Port-Id = "00000004"
        Framed-IP-Address = 172.25.0.168
        Acct-Session-Id = "4ae69d6000000004"
        NAS-IP-Address = 172.25.0.1
        Called-Station-Id = "00-16-B6-D9-5A-EB"
        Acct-Unique-Session-Id = "f3bcc21590c1afd1"
        Timestamp = 1256627577
        Request-Authenticator = Verified*

Then about 1 minute later, the following occurs
*Tue Oct 27 09:13:59 2009
        ChilliSpot-Version = "1.0.13"
        Acct-Status-Type = Interim-Update
        Calling-Station-Id = "00-1F-33-FF-BD-00"
        NAS-Port-Type = Wireless-802.11
        NAS-Port = 4
        NAS-Port-Id = "00000004"
        Framed-IP-Address = 172.25.0.168
        Acct-Session-Id = "4ae69d6000000004"
        NAS-IP-Address = 172.25.0.1
        Called-Station-Id = "00-16-B6-D9-5A-EB"
       Acct-Input-Octets = 1178355
       Acct-Output-Octets = 52201523
        Acct-Input-Gigawords = 0
        Acct-Output-Gigawords = 0
        Acct-Input-Packets = 19170
        Acct-Output-Packets = 36581
        Acct-Session-Time = 63
        Acct-Unique-Session-Id = "f3bcc21590c1afd1"
        Timestamp = 1256627639
        Request-Authenticator = Verified*

This is definitely in error (the bold parts), as the backbone line speed
cannot handle this much traffic in such a short space of time. Another
minute later:
Tue Oct 27 09:15:02 2009
*        ChilliSpot-Version = "1.0.13"
        Acct-Status-Type = Interim-Update
        Calling-Station-Id = "00-1F-33-FF-BD-00"
        NAS-Port-Type = Wireless-802.11
        NAS-Port = 4
        NAS-Port-Id = "00000004"
        Framed-IP-Address = 172.25.0.168
        Acct-Session-Id = "4ae69d6000000004"
        NAS-IP-Address = 172.25.0.1
        Called-Station-Id = "00-16-B6-D9-5A-EB"
       Acct-Input-Octets = 2132628
       Acct-Output-Octets = 98448008
        Acct-Input-Gigawords = 0
        Acct-Output-Gigawords = 0
        Acct-Input-Packets = 36067
        Acct-Output-Packets = 68754
        Acct-Session-Time = 126
        Acct-Unique-Session-Id = "f3bcc21590c1afd1"
        Timestamp = 1256627702
        Request-Authenticator = Verified*

Again, the amount of data usage is absolutely impossible for the backbone's
capabaility. Another minute later:
*Tue Oct 27 09:16:05 2009
        ChilliSpot-Version = "1.0.13"
        Acct-Status-Type = Interim-Update
        Calling-Station-Id = "00-1F-33-FF-BD-00"
        NAS-Port-Type = Wireless-802.11
        NAS-Port = 4
        NAS-Port-Id = "00000004"
        Framed-IP-Address = 172.25.0.168
        Acct-Session-Id = "4ae69d6000000004"
        NAS-IP-Address = 172.25.0.1
        Called-Station-Id = "00-16-B6-D9-5A-EB"
       Acct-Input-Octets = 3097259
       Acct-Output-Octets = 146070592
        Acct-Input-Gigawords = 0
        Acct-Output-Gigawords = 0
        Acct-Input-Packets = 53364
        Acct-Output-Packets = 101854
        Acct-Session-Time = 189
        Acct-Unique-Session-Id = "f3bcc21590c1afd1"
        Timestamp = 1256627765
        Request-Authenticator = Verified*

Again, impossibly high. There is just one more account interim update, and
then the person is logged off due to insufficient credit:
*Tue Oct 27 09:17:14 2009
        ChilliSpot-Version = "1.0.13"
        Acct-Status-Type = Stop
        Calling-Station-Id = "00-1F-33-FF-BD-00"
        NAS-Port-Type = Wireless-802.11
        NAS-Port = 4
        NAS-Port-Id = "00000004"
        Framed-IP-Address = 172.25.0.168
        Acct-Session-Id = "4ae69d6000000004"
        NAS-IP-Address = 172.25.0.1
        Called-Station-Id = "00-16-B6-D9-5A-EB"
       Acct-Input-Octets = 3701744
       Acct-Output-Octets = 175905676
        Acct-Input-Gigawords = 0
        Acct-Output-Gigawords = 0
        Acct-Input-Packets = 64216
        Acct-Output-Packets = 122605
        Acct-Session-Time = 228
        Acct-Terminate-Cause = Session-Timeout
        Acct-Unique-Session-Id = "f3bcc21590c1afd1"
        Timestamp = 1256627834
        Request-Authenticator = Verified*

All in all, chilli has told radius that the user has used 171.29 megabytes
in 3.8 minutes. Of that, 167.76 megabytes were in downloads, and 3.53
megabytes were in uploads. Unfortunately, this is absolutely impossible with
regards to the backbone speeds in South Africa.

Any help would be greatly appreciated, I have no idea how to solve this.

All the best
Jack J Allan
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