Thanks all who replied. Since we have an OC-3 currently I went down the hall and pulled out the actual bill. I was even more confused when I looked at the bill. The situation is as follows... We have 4 DS3s and an OC3 which SBC provides to us via a Nortel mux that they placed on our premise. The OC3 we have now is hooked up to their ATM network to connect up some other high speed sites. On the actual bill for that OC3 it shows a charge for $2200, no more, no less. The service described is "SONET Circuit Service OC3" which I find very puzzling since we don't interface with SBC using SONET. Someone explained this weirdness as "you pay for the OC-3 that is provisioned through their SONET infrastructure of which the premise mux is the last stop". OK fine. So to continue with my current puzzlement, what types of USOCs should I expect to be quoted when provisioning an OC3 for voice? Basted on Matts recommendation it would seem that I need a regular old OC3. Additionally I would expect to see some misc tax and surcharge items; probably some sort of E911 charge as well. Anything else I am missing or do I just tell them that I want the transport plugged into the PSTN and give them the phone numbers that I want to ride on that circuit? Thanks all, Dan -----Original Message----- From: Matthew Crocker [mailto:matthew@crocker.com] Sent: Thursday, April 14, 2005 2:55 PM To: Dan Lockwood Cc: nanog@merit.edu Subject: Re: Anyone familiar with the SBC product lingo?
SONET Circuit Service OC3-c (155Mbps) $2200 vs. Central Office Node Circuit Service OC3/3c (155Mbps) $675
SONET is a method of transporting TDM channels over fiber. SONET is made up of building blocks calls a STS. A STS is equivalent to a DS-3 + SONET Wrapper. An OC-3 equals 3 STSes. OC-3s come in two types, 'channelized' OC-3 which is 3 DS-3s in 3 STSes and Packet Over SONET (POS), concatenated OC-3c which is 155mbps. If you are planning on using this circuit for TDM based voice (84 T1s in 3 DS-3 chunks) then you will want an OC-3 not an OC-3c. If you are planning on running 155mbps POS IP traffic you want an OC-3c. OC-3 = 3 x STS-1 = 3 x DS-3 = 3 x 28 DS-1s, 84 DS-1s = 2016 DS0 voice channels. OC-3c = 1 x STS-3 = 155mbps You can use an Adtran OPTI-3 to break an OC-3 into 3 distinct DS-3 channels which can be plugged into M13 muxes (Carrier Access Widebank 28) which will break a DS-3 into 28 DS-1s. If you want IP bandwidth you can use an OC-3 POS line card from your router vendor of choice. -Matt