Now problem mostly eased, thanks to Moore law, but 20 years ago router memory need to store prefixes-routes graph was very expensive and have some problems with grow.
For example, I know people, bought very expensive server PC boards (but cheap compared to enterprise networking hardware), with DDR2 capability, because it was fastest at that time and promises large RAM space.
Imagine their frustration, when they seen, this hardware cannot allocate prefixes list for their installation (just not enough RAM) and they have to buy new hardware with DDR3.
This even caused "curse of /24", when some providers decided to just discard /24 prefixes and work only with /16 directly and for smaller allocations use some default route.
And this is just because nature of Internet, which is by definition "network of networks", mean, in ideal case all networks should have peer connections at least to all first circle neighbor networks, but better if have peers to few first circles, plus connections to large local hubs.
And now problem become harder, because of grow of p2p solutions, which by definition avoid hub model and use all peers directly.
BTW, colleague from telecom share latest problem - few days ago appear huge traffic. In very short time found source - after appear new "Stalker" game, their developers made huge number of fixes, so fixes are larger than installation, and they somewhere bought so powerful distribution network, distribution of fixes flooded all connections for few days.
It is not the limitation, but router hardware is.
Now problem mostly eased, thanks to Moore law, but 20 years ago router memory need to store prefixes-routes graph was very expensive and have some problems with grow.
For example, I know people, bought very expensive server PC boards (but cheap compared to enterprise networking hardware), with DDR2 capability, because it was fastest at that time and promises large RAM space.
Imagine their frustration, when they seen, this hardware cannot allocate prefixes list for their installation (just not enough RAM) and they have to buy new hardware with DDR3.
This even caused "curse of /24", when some providers decided to just discard /24 prefixes and work only with /16 directly and for smaller allocations use some default route.
And this is just because nature of Internet, which is by definition "network of networks", mean, in ideal case all networks should have peer connections at least to all first circle neighbor networks, but better if have peers to few first circles, plus connections to large local hubs.
And now problem become harder, because of grow of p2p solutions, which by definition avoid hub model and use all peers directly.
BTW, colleague from telecom share latest problem - few days ago appear huge traffic. In very short time found source - after appear new "Stalker" game, their developers made huge number of fixes, so fixes are larger than installation, and they somewhere bought so powerful distribution network, distribution of fixes flooded all connections for few days.