On Sun, 2004-02-08 at 02:42, Ilya Konstantinov wrote:
> Hi Guy,
> 
> Maybe it wasn't your point, but it's all in the best traditions of
> driving a "high level" discussion into technicalities :)
As long as it's not a flame war, I'm with you on that one.
> 
> > When on DHCP, the ISP has no ability to identify and classify the
> > client. Consider the following services that ISPs provide today:
> > - Have not surfed ?  Will not pay. (if the ISP can not identify the
> > customer, the service will not be available to the end user)
> 
> The ISP can identify the user by performing DHCP LEASEQUERY command on
> the cables' Cisco DHCP server. This will return the modem's MAC
> address, which identifies you as a subscriber.
Problematic... If you are "pure DHCP" customer, you get the IP from the
cables company and not your ISP. The ISP allocates a DHCP pool for this
purpose and the cables company maps the cable modem's MAC to appropriate
DHCP pool. As the DHCP is provisioned by the cables company, the ISP has
no real control over the logs, etc... Even if the ISP has appropriate
access, they would rather prefer to handle this by in-house means.
This brings us to the logging issue: ISP has no on-line access to DHCP
server logs and history (consider abuse investigation involving an
expired DHCP lease). Well... you get the point. 

> I don't know what cable solutions other vendors have. The Israeli
> cables use Cisco (according to their MACs :).
Indeed.

> 
> > - QoS and prioritizing. With DHCP the ISP has no ability to treat each
> > end connection separately and can only shape the traffic as a whole.
> 
> Not familiar with the technology. Shaping on the IP level (by source
> IP) doesn't work very well?
I am not a traffic shaping guru, but from what I understand, each tunnel
client can be shaped/policed where the tunnel terminates as you are
dealing with an interface and are not filtering based on some criteria.
Shaping based on IP will require additional overhead on the routers. 
And what about the cases when you have a mail server spreading SPAM
which is spoofing it's source IP address ? You can easily block the
wrong customer if you are dealing only with source IP.

> 
> > - Have you considered the legal sides ? How can abuse department track
> > down a customer with is abusing the net ?
> 
> See above.
See above :-)
> 
> > - How do you track a client which is spreading SPAM from his computer ?
> > (no tunneling = no easy way to trace back the abuser)
> 
> See above.
See above :-)


Guy
-- 


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