Hi. I have only recently been following this discussion. I am curious re:
why availability is not a metric/parameter or if and how it is implict in
the 4 parameters stated below. I would also imagine that for any of these
parameters some min, max or average value could be specified in the SLA
either individually or as a bounding set.
"Yves T'Joens"
<yves.tjoens@al To: sls@ist-tequila.org
catel.be> cc: "'Gabor.Fodor@era-t.ericsson.se'"
Sent by: <Gabor.Fodor@era-t.ericsson.se>
owner-sls@ist-t Subject: Re: [tequila/sls] Comments on
equila.org Tequila / SLS draft
11/03/00 10:54
AM
Please respond
to sls
> "Kamal Bath (EPA)" wrote:
>
> Hi,
Hi Kamal,
>
> We have been discussing the Tequila draft and have two points that
> we'd like
> to raise.
>
> 1) Section 3.5 of the draft discusses Performance Guarantees using
> four
> parameters: delay, jitter, packet loss and throughput and these
> service
> guarantees may be quantitative or qualitative.
>
> Something we consider essential is a definition of time periods to use
> in
> measuring the SLS, i.e. whether these parameters represent the overall
>
> average for the entire duration of the SLS or whether they indicate
> the
> worst acceptable time periods for the SLS duration.
>
> An interpretation of an SLS over 2 months with a specified packet loss
> of
> 10E-3, could simply require the average packet loss over the entire 2
> months
> to be less than 10E-3. If a time period (e.g. 1 hour) is specified,
> then the SLS
> would require the average packet loss over any 1 hour period within
> the 2
> months to be less than 10E-3.
>
> Obviously, the 2 SLSs above are quite different in requirements, and
> it is
> important for the customer to be able to clearly define the SLS
> service
> required.
this introduces in fact the requirement for another parameter in the
SLS, unless we can find a single solution for that...which i doubt.
>
> 2) The second issue we would like to raise is the concept of blocking
> and
> associated probability. We can see a use for a second type of SLS for
> connection oriented services. In this SLS, the user defines the
> characteristics
> either for the aggregate traffic level or for the individual flow, as
> well as a traffic
> profile (inter-arrival times, holding times, Bandwidth, etc) and
> blocking probability
> for the individual connections.
>
> When the individual connections are established, an admission control
> request is made for them. The operator may thus reject individual
> sessions,
> but the SLS defines what level of these services the operator should
> dimension for. This may allow the operator to oversubscribe their
> network.
>
> The advantage with this SLS for the user is they can maintain
> stringent QoS
> per flow requirements due to the admission control, even when the
> network is
> oversubscribed.
>
potentially the framework draft may have already shown you that the
above is within scope. it makes me think about the difference in
subscription and invocation.
cheers
Yves
> Regards,
> Gabor and Kamal
-- +------------------------------------------------------------------+ | Yves T'Joens | | Project Manager Internet Access and Edge | | Network Strategy Group | | Francis Wellesplein, 1 phone : +32 (0)3 240 7890 | | 2018 Antwerp fax : +32 (0)3 240 9932 | | Belgium email: yves.tjoens@alcatel.be | +------------------------------------------------------------------+
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