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RE: new version of the CPE Rtr draft is ready for review



Teemu,
 
Thanks very much for the review.  I and Wes discussed your comments and here are our responses back in line between <hs> </hs>.


From: teemu.savolainen@nokia.com [mailto:teemu.savolainen@nokia.com]
Sent: Wednesday, November 12, 2008 10:25 AM
To: Hemant Singh (shemant); v6ops@ops.ietf.org
Subject: RE: new version of the CPE Rtr draft is ready for review

Hi,
 
I like this document a lot, and really look forward to get this forward.
 
Few comments:
- 5.4. says that CPE router has failed DHCPv6 address acquisition if IA_PD option is not included in ADVERTISE/REPLY in stateful DHCPv6 case. Now considering case where a CPE router is embedded into mobile host that is attaching to different networks, some of which may mandate DHCPv6 use and some of which don't: if the mobile host always asks for IA_PD, but sometimes doesn't get it (due differencies in network policies), isn't the address acquisition process still successful for the host itself, but just not for CPE router function of the host? I mean could this section be clarified to state that in such case the address acquisition is only partially succesful? And perhaps that in such case the CPE router can configure the IPv6 address for itself and at the same time initiate other-but-less-preferred means for providing Internet connectivity to LAN side, such as fall-back to IPv4-only CPE router functionality, bridging, (NATting between ULA and global IPv6 address...), or doing ND proxying?
 
<hs>
Good catch.  This section missed the zero-LAN case.  We can modify text in this section to say something like "the CPE Router software knows its running in a zero-LAN hardware device and in such a case of zero-LAN hardware, if an IA_PD is not asked for by the CPE Router, nor does a DHCPv6 response received by the CPE Router includes the IA_PD Option, then there is no error deemed. 
</hs>
 
- Is there a reason why ND Proxy (RFC4389) is not mentioned? Because it is of experimental category? 
 
<hs>
Partial reason.  But we have not found a need for the CPE Router to support ND Proxy just yet.  If any deployment still thinks that the CPE Router MUST support an ND Proxy, please contact us and we will evaluate the deployment and the need.
</hs> 
 
- 5.5.2. one scenario for WAN initialization before LAN is that LAN side is not initialized at all without external host first connecting to CPE router by some technology. Again cellular use case: a mobile has always-on WAN connectivity for usual uses (VoIP/email/MMS/browsing) and a host (say PC) initiates WLAN/Bluetooth/USB/whatever connection to a mobile only much later than initial WAN connection was created. In such case the trigger for requesting IA_PD would be initialization of LAN side physical interface (e.g. triggering of Bluetooth PAN profile), as asking for IA_PD at the moment of WAN initialization would unnecessarily reserve prefixes by hosts never utilizing those.
 
<hs>
We can modify this section's 1st para, 2nd line to change from
 
[After the IPv6 address configuration for WAN interface is completed, the CPE Router configures IPv6 address for LAN interface(s).]
 
to
 
[After the IPv6 address configuration for WAN interface is completed, the CPE Router may configure IPv6 address(es) for any LAN interface(s).]
 
Further, in the 2nd paragraph, a portion of the 1st sentence of the same section changes from
 
[Once IPv6 address configuration of the LAN interface(s) is complete, ]
 
to
 
[When and if  IPv6 address configuration of the LAN interface(s)  completes, ]
 
</hs>
 
- 5.6. IPv6 over Ethernet and PPP are not the only existing technologies and possibly more are coming, Maybe this chapter should be generalized? Examples of other technologies are:
   * RFC5121 Transmission of IPv6 via the IPv6 Convergence Sublayer over IEEE 802.16 Networks
   * RFC3574 Transition Scenarios for 3GPP Networks (which is somewhat incomplete now as 3GPP has made some rather significant changes to bearer concepts since 2003)
 
<hs>
We need to think about this one.
<.hs>
 
- Could CPE router utilize RFC5006 on LAN and/or WAN interfaces?
 
<hs>
We personally have not accepted this RFC and it's also an experimental one.  See more below against your DHCPV6 server comments.  Again, unless a deal-breaking need is found where this RFC MUST be supported by the CPE Router, we will skip this RFC in our document.
</hs>
 
- Is stateless DHCPv6 server or DHCPv6 relay SHOULD or MUST for CPE router to provide hosts in LAN with access to other configuration parameters available from service provider's DHCPv6 server?  I.e. not just for reasons described in chapter 6. 
 
<hs>
Yes, at least a stateless DHCPv6 server is needed to pass Service Provider options to the LAN device(s).  We think section 5.7 can be renamed to "DHCPv6 Server" and then we can discuss both stateless and stateful DHCPv6 servers in the section.
<hs> 
 
- 8.7. could/would/should this perhaps relate/mention to this draft: http://tools.ietf.org/html/draft-bellis-dnsext-dnsproxy-00 ?
 
<hs>
Wes is on top of this section.  He will read your draft pointer above and we will reply a little later on this one.
</hs>
 
- As several transition mechanisms are being worked on, the 8.6 should perhaps mention that DS-Lite is not the only mechanisms that may cause this chapter to be updated.
 
<hs>
We do say in this section that several proposals are out there.  However, we should probably mention more than just DS-Lite.
</hs>
 
If you wish, I can contribute text from cellular perspectives. 
 
<hs>
If you are coming to IETF 73, let's get together and discuss this.  We are presenting this draft in v6ops.
</hs> 
 
Thanks.
 
Kind Regards.
 
Hemant & Wes.
 
 
Best regards,
 
    Teemu
 


From: owner-v6ops@ops.ietf.org [mailto:owner-v6ops@ops.ietf.org] On Behalf Of ext Hemant Singh (shemant)
Sent: 30 October, 2008 19:29
To: IPv6 Operations
Subject: new version of the CPE Rtr draft is ready for review

http://www.ietf.org/internet-drafts/draft-wbeebee-ipv6-cpe-router-03.txt
 
Thanks.
 
Hemant & Wes