Michael.Dillon@radianz.com writes:
On the contrary, you get better redundancy by sticking to one carrier and making sure that they really provide separacy though the entire span of the circuit. If you have two carriers running fibre to yoiur building down the same conduit, then you do NOT have separacy and as a result, the redundancy is not there.
The problem with this theory is that one carrier is completely free to reroute your connectivity among its resources. Two carriers can certainly move from being diverse relative to each other to sharing common infrastructure, but if it costs money it's much less likely to happen. Note that many carriers, though perhaps not the LECs, will answer questions about the underlying resources they are using if they are sufficiently motivated, but you have to reask every now and again to make sure that the answers are still satisfactory.
Of course, you can get separacy with two carriers but it is generally more work to verify that the two companies do not share fibre or conduit or tunnels.
Well, then it's a question of how much one cares about diversity. If it's important, it may be worth some effort. If it's really important, then you try harder to control the infrastructure in question directly, which can mean anything from constructing your own underground facilities to leasing someone elses - at least to get out of the building. If it's really, really important, then you pick the building based on the selection of providers and the redundancy offered by the set.