Subject: Re: [Softwires] More changes to revision 03. - Sent again in text

From: Ole Trøan <[email-masked]>
Date: Wed, 1 Feb 2012 15:01:02 +0100

Leaf,

> Rajiv - I would very much favor having a sharing ratio as a 'given' variable.
> 
> Though Rajiv prefers 'sharing ratio' to 'EA-bit length', which is a little different from the text of section 5,
> 
> I'd also like the draft could define an explicit format for the expression of the MAP rules including BMR, FMR & DMR.

the current document specifies which parameters make up the rule. the only time a rule would be passed on the wire is for provisioning, it is explicitly defined in the DHCP option draft.

> BTW, more questions on the example of DMR in section 5.4,
> 
> <Quote> - {2001:db8:0001:0000:&lt;interface-id>:/128 (Rule IPv6 prefix),
> 0.0.0.0/0 (Rule IPv4 prefix),
> 192.0.2.1 (BR IPv4 address)}
> 
> Q1.  What does ‘&lt’ mean here?

XML artifact. '&lt' => less than => '<'

> Q2.  Does ‘interface-id>:/128’ sound a prefix here?

yes. MAP-T forwards traffic towards a "default prefix", while MAP-E sends to an address.

> Q3.  Is the BR IPv4 address (192.0.2.1) necessary here? There seems no IPv4 address in the BMR & FMR, but they also work well for the MAP forwarding function.

if the Rule IPv4 prefix is used to indicate default route 0/0, then there is nothing to give the IPv4 prefix part. so the complete address is given as a parameter. this is to help implementations requiring that the next-hop is of the same address family as the route in the RIB. it will never make it onto the wire, so strictly speaking it isn't needed. useful for troubleshooting though, so that you can IPv4 ping your default router.

cheers,
Ole