RE: [802.21] HLSI
Hi Yoshi, good that you're reviewing the IS. Some comments below.
Stefano
________________________________
From: ext Yoshihiro Ohba [mailto:yohba@TARI.TOSHIBA.COM]
Sent: Mon 9/5/2005 10:58 PM
To: STDS-802-21@listserv.ieee.org
Subject: [802.21] HLSI
I am currently writing up a contribution to revise Information Service
sections and I have the following questions:
The HLSI IE defines several flags indicating the available higher-layer
services including ISP, MMS, IMS, MIP, VPN, SIP and NAT.
- What is the exact meaning of "VPN support"? Does it mean that if
you connect to the PoA then all data traffic will be automatically
forwarded to some remote network over a dedicated tunnel between the
PoA and the remote network? Or does it mean that the network provides
a VPN gateway? Or does it mean that the mobile terminal connected to
the PoA can establish a VPN connection to any VPN gateway. Or
something else? The first definition does not make sense because you
will need additional information about the remote network to make a
handover decision. The latter two definitions do not make sense
either, because there are several different ways of establishing a VPN
connection (i.e., IPsec, SSL, L2TP, PPTP, etc.) and you will need
additional information as to which VPN method is used to make a
handover decision.
[Stefano] my udnerstanding was that "VPN support" means the network would allow the terminal to use VPN. I think the indication is useful, but needs perhaps more details. E.g. indication that IPSec-based VPN traffic is allowed (i.e. the entwork will not block it) is useful, since if the traffic requires IPSec-based VPN then that access is not a candidate.
- What is the exact meaning of "SIP support"? Does it mean that the
network has a SIP server or proxy, or something else?
- Do we really need HLSI IE defined in the basic set? I think it can
be defined in extended set. This is because we might need more
detailed information about higher-layer (such as IP addresses and
prefixes of access routers, supported IP mobility optimization
mechanism, list of supported ISPs, etc.) to make a higher layer
information and just defining a set of flags seems like a half-baked
solution. Such detailed information can be provided via schema-based
query by which various higher-layer (and lower-layer) MIB objects can
be retrieved once converted to RDF data.
Regards,
Yoshihiro Ohba