On Tue, 16 Aug 2005, Dean Anderson wrote: > the current draft doesn't even contain the word 'balancing' or > 'balance' except to talk about the balancing of load between > anycast nodes. It doesn't address AT ALL the impact of fine grained > load balancing of packets on routers, an issue that seems pretty > well-suited to GROW.
I believe that the above part of Dean's criticism is valid, and I think that it would be worthwhile for a section on per-packet load balancing to be added to the draft. This section could point out the places where PPLB is or is not likely to interact badly with anycast services that require multiple packets. For example: per-packet load balancing across multiple parallel links between the same pair of routers is almost always safe; per-packet load balancing across diverse paths within your own AS, but where the paths converge before exiting your own AS, is likely to cause performance problems traceable to packet re-ordering, but these problems are unlikely to be any worse with anycast services than with non-anycast services; per-packet load balancing across links to different neighbouring ASes (such as different upstream providers) may cause serious problems with anycast services that are implemented according to the suggestions in this draft, because the different links might lead to different instances of the anycast service; I suggest that the draft could recommend "don't do the problematic types of load balancing", and could observe that hardly anybody does the problematic type of load balancing anyway. This is opposed to Dean's apparent preference for recommending "don't do anycast for services that use TCP". --apb (Alan Barrett) _________________________________________________________________ web user interface: http://darkwing.uoregon.edu/~llynch/grow.html web archive: http://darkwing.uoregon.edu/~llynch/grow/
