Re: Distribution CPG Protocol

[Oliver Spatscheck <spatsch@research.att.com>]

brad cain writes:
 > 
 > 
 > Stephen,
 > 
 > 
 > First, I will second Alex's opinion that this protocol is
 > really about about the content routing problem
 > 
 >  
 > > Is there consensus that the distribution protocol operates in three phases?
 > > 
 > >    1. CDN advertises its capabilities
 > >    2. The Content Provider requests the use of CDN services by identifying
 > > content to be distributed.
 > >    3. The CDN confirms (or denies) the request for service
 > 
 > I'll push back on stage #3... It looks like "inline qos" to me... what
 > I mean by this is that I don't think we should be negotiating any type
 > of QoS in the protocol... I would say you just advertise to your
 > neighbors
 > and make sure the off-line SLAs cover any QoS... 

I think step 3 is rather confirming availability of service than defines QoS
(I guess availability is one type of quality so you could say its QoS .). In
an previous email I described the case in which a CDN advertises the same
capacity to many other CDNs. If one of the CDNs uses the capacity the
second CDN requesting the use of the CDN should be denied the use
since the first CDN was faster. I do not envision complicated negotiations
in phase 3. It is a simple yes or no. Without step 3 the advertising CDN
can never advertise the same capability to multiple other CDNs which
seems very wasteful.


Oliver