From: Alastair Johnson [mailto:aj(a)sneep.net] Sent: Thursday, 21 December 2006 12:26 p.m. To: nznog(a)list.waikato.ac.nz Subject: Re: [nznog] Connection reliability (was Re: Telstra's Outage) [...] To compliment Donald's question a little more (the answer, Donald, is "more DSLAMs = more redundancy, right?"), LLU doesn't help that much either.
Let's suppose that right now you have n customers attached to a Telecom DSLAM. Zap! Regulate! Unbundling takes place. iCuddle, Nazgulon and maybe other ISP's to a total of m ISP's all install their own DSLAM's in the exchange building and all build redundant access networks from there back to a redundant core. For some values of "redundant". Suppose all are equally successful at attracting customers. Then a single failure can affect no more than n/m customers as opposed to n previously. But more parts for a given MTBF means more failures. The availability of service to any single end user only improves at the point at which something is built which is _more_ reliable than what was there before. - Donald Neal Donald Neal | The correct answer to any Alcatel-Lucent | engineering question about Support Engineer | network traffic is "it depends". Technology Operations | - Priscilla Oppenheimer HTC, Caro Street, Hamilton +--------------------------------- This communication, including any attachments, is confidential. If you are not the intended recipient, you should not read it - please contact me immediately, destroy it, and do not copy or use any part of this communication or disclose anything about it. Thank you. Please note that this communication does not designate an information system for the purposes of the Electronic Transactions Act 2002.