Re: [RPRWG] RPR Perf: Non-uniform distribution
Actually, in several of our larger rings, we currently have 2 to 4 points with
connections to our core. With most LEC infrastructure being OC48, I can only
see this trend continuing. On the other hand, in most major markets, there is
only one POP (depending on who your long haul connection is). (just the @Home 2
cents)
Komal Rathi wrote:
> Hi Jeff,
>
> I agree with you that there will probably not be high multi-homing within a
> MAN ring in the near term. A more realistic scenario will most likely be 2
> or more hubs (POPs) on the ring and unequal traffic going "off-ring" at each
> hub. Do you have any suggestions for a set of realistic non-uniform traffic
> patterns?
>
> Thanks,
> Komal
>
> -----Original Message-----
> From: Timbs, Jeffrey L (Jeff) [mailto:timbs@xxxxxxxxx]
> Sent: Thursday, April 26, 2001 6:04 AM
> To: 'stds-802-17@xxxxxxxx'
> Subject: RE: [RPRWG] RPR Perf: Non-uniform distribution
>
> Khaled et al:
> I agree with Komal's suggestion below. I would like to see the behavior when
> a large % of traffic goes "off-ring" through few (1 or 2) nodes. It has been
> reported that pass-thru : add/drop traffic is higher than 80:20 due to the
> long-distance nature of IP traffic. [Rodriguez-Moral et al, "Optical Data
> Networking," Journal of Lightwave Technology, Vol. 18, No. 12, December
> 2000] A further implication is that most IP traffic is not terminated within
> a MAN, leading to hot-nodes (or gateways) which are destinations of the
> majority of traffic. Assuming that MAN rings are connected to backbone
> networks via few (one or two) nodes, a high percentage of traffic will be
> destined for these few nodes.
>
> Some interesting points are that, of 100 "leading" websites, WorldCom could
> carry traffic to up to 45 of them entirely on its own backbone while MCI
> could reach 28 sites directly (Sprint, 18 sites). Also, 35 of the sites
> were multi-homed on the WorldCom backbone. [cf. OECD pub
> DSTI/ICCP/TISP(98)7/FINAL via http://www.oecd.org/dsti/sti/it/cm/index.htm]
>
> It's not clear that there would be a high degree of multi-homing within a
> MAN ring (an economical factor driven by localized demand). For a high
> degree of destination stripping distributed across many nodes, several
> services would need to be offered at many sites (POPs). To me, there is a
> current assumption that new service providers want to populate as few POPs
> as possible, so that traffic must be carried to a centrallized site within a
> region which also decreases the likelihood of uniform distribution.
>
> For near-term introduction of RPRs, we should consider that this traffic
> pattern may be more representative of a MAN RPR and should consider the
> impact on performance (due to lower overall spatial reuse).
>
> Jeff Timbs
> Agere Systems, Inc.
>
> -----Original Message-----
> From: Komal Rathi [mailto:krathi@xxxxxxxxxxxxxx]
> Sent: Tuesday, April 24, 2001 1:50 PM
> To: 'stds-802-17@xxxxxxxx'
> Subject: [RPRWG] RPR Perf: Non-uniform distribution
>
> Khaled and members of the Perf. Adhoc committee,
>
> Given that all implementations seem to have destination stripping that
> results in spatial reuse, it's not clear in my mind what we gain out of
> running simulations with randomly and uniformly distributed
> source/destination pairs. I believe that the uniform distribution will not
> provide enough information that would help demonstrate the differences in
> performance characteristics of various proposed architectures. All it does
> is show that we get some spatial reuse, which we know all implementations
> do.
>
> I would like to suggest that we make the destination addresses distributed
> non-uniformly which can show some more interesting performance
> characteristics of various architectures that are being proposed. For
> example, how about something like 80% to dest-A and some other distribution
> to other destination nodes. Another idea would be to have 90% to neighboring
> node A, and 10% to the other neighboring node B.
>
> Komal Rathi
> Lantern Communications
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