All right, DHCPINFORM would work, sounds a bit contorted to mix PPP and
DHCP, but why not. This is what 3GPP2 does, I believe.
Thanks for the historical background.
-----Original Message-----
From: James Carlson [mailto:james.d.carlson at sun.com]
Sent: Monday, October 02, 2006 10:21 AM
To: Jerome Moisand
Cc: pppext at ietf.org; alessandro.cotroni at accenture.com
Subject: RE: [Pppext] TISPAN proposal for PPP IPCP extension to
handleP-CSCFaddress???
Jerome Moisand writes:
Providing a SIP-proxy (P-CSCF) server @ via IPCP does make sense
though.
Not to me.
Might be a good idea to address the problem in a constructive manner,
adding a mechanism for vendor-specific (or organization-specific)
parameters that could be conveyed via IPCP.
See RFC 2153. We already have a vendor-specific extension mechanism
for PPP.
Allowing extensions without
creating interoperability problems, and without the burden of having
to
go to IETF for defining such extensions.
Actually, it still does cause interoperability problems, as it forces
everyone else (over time) to implement these unnecessary extensions.
DHCP and many other protocols have such extensibility, why not IPCP?
IPCP configures the network layer. IP addresses on the link are
network layer properties, but SIP server addresses are application
properties.
Note that RFC 1877 is a Microsoft-proprietary extension.
Was this topic discussed in the past?
Many, many times; see the archives for discussions about SIP server
addresses, DNS server addresses, and other bits of application
configuration. You can use DHCP to handle this application issue, and
it works fine over PPP. DHCPINFORM seems particularly well-suited to
the job, and it's the long-established consensus of the working group
participants that we don't need IPCP extensions like that.
