Subject: [SIP] DHCP for SIP proxy configuration - status update

From: Henning Schulzrinne <[email-masked]>
Date: Wed, 21 Mar 2001 21:33:22 -0800

The DHCP option for locating SIP outbound proxy servers was discussed at
the first DHCP WG meeting. A number of suggestions were made, including
use of a 'marker byte' to indicate the type of address that follows (RFC
1035, host name string, dotted quad).

Investigation after the meeting confirmed that recent versions of ISC's
dhcpd can indeed support such a structured field for 'unknown' options
(i.e., options that have not yet been standardized). However, Windows
2000/NT cannot. Like many older servers (e.g., the Sun DHCP server), it
only allows single atomic data types (string, flag, hex-digit string)
for unknown options.

Thus, based on this issue and in the interest of making forward progress
and given the trade-offs involved (flag bytes allow for additional error
possibilities if flag byte and content disagree), I believe general
consensus was reached to retain the current mechanism and make sure the
draft explains that

- it should be a FQDN, no dot at end
- implementations need to be diligent about recognizing dotted quads

This draft has been bouncing around between the two working groups for a
while, so I appreciate quick comments if somebody disagrees strongly AND
has a viable alternative proposal.

Thanks.

Henning

_______________________________________________
This list is for continuing development of the SIP protocol.
The sip-implementor's list is the place to discuss implementation,
and to receive advice on understanding existing sip.
To subscribe to it, send mail to 
[email-masked] with "subscribe" in the body.