most recent 30 from http://mrwatsoncomehere.com 2010-07-30T02:45:21Z http://mrwatsoncomehere.com/feeds/question/11 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mrwatsoncomehere.com/questions/11/what-is-an-express-orderwire Bruce Fitzsimons 2009-10-20T03:33:16Z 2010-07-27T15:22:57Z

<p>SDH has a byte set aside for a 64Kbps voice channel in the header (byte E2) with the title MS orderwire byte. </p> <p>Why? What is this for?</p>

http://mrwatsoncomehere.com/questions/11/what-is-an-express-orderwire/12#12 Bruce Fitzsimons 2009-10-20T03:35:14Z 2009-10-20T03:35:14Z

<p>An express orderwire is a dedicated voice channel between two points, the TIA define it <a href="http://www.tiaonline.org/market%5Fintelligence/glossary/index.cfm?term=%26%23%24K%5BSB%3BK%0A" rel="nofollow">here</a>. In SDH Transport terms it is a dedicated byte per header that effectively gives a 64Kbps channel between two points.</p> <p>Transport engineers think a lot differently to LAN/WAN people in this respect, Ethernet has no such concept, nor does ATM to my knowledge. I know this concept exists for electricity-related systems though.</p> <p>Anyone with any more information? Is the byte used on every SDH header? Even for STM-256s? (Isn't that more than 64Kbps?)</p>