Sunday August 10, 2008 Random ramblings
Sunday August 10, 2008 Wholesale DSL reform: Possibilities...
Following on from my, somewhat rambling, post on wholesale DSL, here I'll speculate on possible reforms that could be made.
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Micro-peering.
Alluded to as one of the "difficult to do" solutions. It's not at all viable today, but its interesting to consider what improvements would need to be made to internet protocols for this option to at least be possible. E.g. BGP is extremely management intensive. Even simple, non-protocol changes like better defaults could make a difference here. In terms of protocol, things like in-band transfer of policy information and auto-configuration of neighbours could simplify management greatly.
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Allow the telco's own ISP to switch IP locally, where it wishes.
In other words, allow the telco-ISP run a single IP data-plane at the head-end for its own DSL customers, so allowing local switching of traffic within an exchange, if the telco-ISP so desires. At the moment, regulations would tend to prevent the telco discriminating between its wholesale-ISP customers and its own ISP in such a way. If it's the case that there are enough trunk-link bandwidth savings to be made to outweigh the initial costs of re-engineering and further additional managements costs, then it'll happen (at which point there'll be the tricky problem of what to do about the wholesale-ISPs not enjoying this advantage). If not, we'll know it doesn't matter - no harm done. I.e. loosen the regulations so that we can at least allow one player to obtain data on whether we need to re-think whole-sale DSL..
This probably wouldn't work in the UK, where BT appears pretty well divided up. Might still work in Ireland, where Eircom appears still to be a single entity.
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Consolidate network layer responsibility in one company
The benefits of the wholesale-DSL model in terms of the economic-efficiency of the network are actually negative[2]; both in terms of the congruence of IP/geography and in terms of the significant additional complexity and points-of-failure[1], which incur direct costs (engineering and sustaining) and indirect costs (more downtime for customers). Further, managing an IP network is well-understood, and the reliability of the whole-sale ISPs is reliant on the operational competence of the telco.
The benefits of the competition introduced by the wholesale-DSL model therefore must lie primarily in customer-facing services. Therefore we could reform things by allowing the telco to manage the entire network stack (terminating PPP where it wished, assigning IPs, etc..), while leaving customer-services and further value-added services (domains, email accounts, etc..) to the "ISPs".
1. E.g. in Ireland, the few (4 odd?) "BRAS" routers operated by Eircom, which exist to dispatch PPPoE sessions to the various ISPs, via L2TP/IP. The wholesale-ISP must operate their own access-routers in addition to the "BRAS" - with obvious implications for failure rates. In a simpler model, such dispatching wouldn't be needed and PPP sessions could be terminated on cheaper (and so more numerous and perhaps more widely distributed) access-routers.
2. As per previous post: determined by comparison with single-operator networks.
( Aug 10 2008, 05:41:30 PM IST ) Permalink Comments [0]
