On Sat, Oct 22, 2011 at 08:19:33PM +0400, Pavel Lunin wrote: > > As far as I understand, it's not really correct to compare difficulty > of these two operations, since they are performed by two different > units inside the chip. While label lookup instead of full IP table can > dramatically simplify the lookup unit's life, the unit, which inspects > packets and extracts bits from them, must be still quite complex even > for label-only router. Hashing ALU's life is not a peace of cake > either. Say, EX series PFE use only 6-bit seeds to construct hash on > them. In case you want to push a whole 20-bit label to the hash seed, > I'm afraid, you'll need more bits in ALU registers, more cycles or > something else.
Well, nobody said it was EASY, just EASIER. :) The point is, just by going from full tables to not-full-tables you can start taking advantage of existing commodity chips which CAN do IP and some pretty deep hashing already, and move from thousands of dollars per 10GE and 80-120G/slot (MX/ASR-style) down into hundreds of dollars per 10GE and 480-640G/slot. Personally my take is that PTX missed the mark as far as interesting target customer size goes. There are still a *LOT* of places where you could very easily replace a $1mil core T/CRS box at $retardecarrier with a $10-20k 1-2U box that does 64x10GE, or 40GE, etc. But obviously Juniper doesn't want to canibalize from their own T (or at worst MX) market, which is why only made the PTX product that they did (pick between massive or super-$%^&ing massive, and at only ~MX-style port prices). Eventually someone will come along and realize that there is an untapped market here, and then the promise of cheap label switching routers will be fulfilled. IMHO the reasons this hasn't happened yet are a) only Cisco/Juniper *REALLY* have a good handle on the software side of MPLS, and b) not enough non-carriers are currently running (or even currently able to conceptualize running) label-only cores. Of course the large carriers with the most to gain also tend to be the least innovative and the most unwilling to consider cost when designing their architecture, until they go bankrupt of course. :) -- Richard A Steenbergen <r...@e-gerbil.net> http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC) _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp