Talk:Ethernet over SDH

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Merge[edit]

I don't know much about the ENet side of things, but I know that SDH and Sonet are only a few bits off... — RevRagnarok ^{Talk Contrib} 03:06, 25 July 2006 (UTC)[reply]

Especially from the higher level perspective of EoS, they perform identically. They definitely should be merged... whichever one survives (or maybe the combined article could be called Ethernet over SONET/SDH) could use "EoS" in the text so people could read in their mind it as either Ethernet over SDH or Ethernet over SONET. Mrand 03:15, 25 July 2006 (UTC)[reply]

I just stumbled on the two pages when I was trying to find what else linked to the horrible mis-spelling of Sychronous Digital Heirarchy. ;) — RevRagnarok ^{Talk Contrib} 03:18, 25 July 2006 (UTC)[reply]

Definitely merge: SONET and SDH are basically the same (SONET is a regional variant of international SDH). The set of protocols refered to by EoS is agnostic of any perceived differences between SONET and SDH. BertK 06:49, 12 October 2006 (UTC)[reply]

EoT and EoPDH[edit]

There is also Ethernet over Transport (EoT), a generic term, and Ethernet over PDH (EoP or EoPDH), the same set of protocols but run over PDH servers. BertK 06:49, 12 October 2006 (UTC)[reply]

The bandwidths table is correct?[edit]

I know something about SDH technology and I think that have some errors in the Payload Capacity column... One STM-1 supports up to 63 E1's, but the table indicates 1 to 64 vc-12. In the same way, one STM-1 supports 3 vc-3, thus one STM-64 supports 192 vc-3, not 256. I don't know much about SONET, but I think the capacities are the same of SDH... Sidneytodo (talk) 21:37, 17 June 2008 (UTC)[reply]

Yes, capacities are the same for SONET and SDH. I am not a expert on low-order, but I don't remember there being a restriction that a VirtCat group must fit within an STM-1. The number 64 comes from the low-order sequence numbers being stored in a 6-bit field. Those 64 E1's can be spread across any number of STM-1's. Same for high order. The 256 limitation comes from an 8-bit sequence number field. Those 256's can be spread across multiple OC-192/STM-64 pipes. —Mrand ^{Talk • C} 03:49, 18 June 2008 (UTC)[reply]

Interleaving do not add security[edit]

To quote from the article "As this is byte interleaved, it provides a better level of security compared to other mechanisms for Ethernet transport". Byte interleaving does not add security, if we by security we mean protection against attacks by an adversary. Byte interleaving, which is used by many protocols adds protection against random bit errors (and to some degree against burst errors). But this mean that interlaving adds robustnesss, resilience - not security.