No Subject

3. Call leg lookups are now oodles easier, since they are just based on 
case-sensitive string compares. No more messy URL comparisons. However, its
worth noting that you can still do this anyway, since tags have to be
globally unique. That is, even though the spec says its the full
To/From/Call-ID, you could just use tags/Call-ID to index legs at a UA. What
you wouldn't be able to do is change the From/To URLs in subsequent
requests, as above in (2).

4. The Replaces header gets shortened; its now easier to identify the call
leg 
thats getting replaced. May not be a big deal.

5. This may work with existing proxies, but has compatibility issues with
existing 
UAs. A simple SUpported token would handle this, though.


Given that (1) is moot, (3) is possible without this proposal, (4) is not
too important, the only real benefit is (2), that you can send the right