Re: Very fast IP, no ATM...

[Peter Lothberg <]

> Could anybody help me a bit with SONET/SDH technology:
> what is the present state of - say STM4c vs STM4  etc.-
> standardization.

I think you are mixing Sonet and SDH terminology here,
both SDH and Sonet are vell standardized upto 622.

Speed	SDH		Sonet
-----------------------------------------
155M	STM-1		OC3c
622M	STM-4		OC12c

> At Stuttgart we run some 20km dark fibre driven by FORE`s
> ATM/STM4c boards (NEC SX4 32 - Cray T3E 512) - would
> we buy e.g. NORTEL  SDH equipment if this would be -
> say 100km - and what about public European  SDH?

I can't answer, as you mix names.

But, for the two speeds mentioned above, both Sonet and SDH 
transport equipment could be configured to carry either of.

The tricky part is how to configure protection, and that's
the same for both Sonet and SDH.

> How is vBNS going to upgrade to 622Mbit/s ?

(Not my department) but I think they use ATM switches.

> What does the the below  "Cisco's Native IP over SDH/VC4"
> exactly say?

Read the RFC on PPP over Sonet, but here is how it's stuffed into a
container, and note I don't do PPP on the link we talked about, just
cisco HDLC.


      |<--------------------------------------------------270 Bytes-------->|
      |<--------------9 Bytes------------>|<1B>|<---------260 Bytes-------->|

 --   +---------------------------------------------------------------------+
      | A1| A1| A1| A2| A2| A2| J0| Z0| Z0||J1||                            |
      |-----------------------------------||--||                            +
 SOH  | B1|   |   | E1|   |   | F1|   |   ||B3||                            |
      +-----------------------------------||--||      HDLC byte stuffed     +
      | D1|   |   | D2|   |   | D3|   |   ||C2||        inserted here       |
 --   +-----------------------------------||--||                            +
 --   +-----------------------------------||--||    Synchronous Payload     +
 Point| H1| H1| H1| H2| H2| H2| H3| H3| H3||G1||       Envelope (SPE)       |
 --   +-----------------------------------||--||                            +
 --   +-----------------------------------||--||                            +
      | B2| B2| B2| K1|   |   | K2|   |   ||F2|| ----------------------------||--||                            +
      | D4|   |   | D5|   |   | D6|   |   ||H4||                            |
      +-----------------------------------||--||                            +
 LOH  | D7|   |   | D8|   |   | D9|   |   ||Z3||                            |
      +-----------------------------------||--||                            +
      |D10|   |   |D11|   |   |D12|   |   ||Z4||                            |
      +-----------------------------------||--||                            +
      | S1| Z1| Z1| Z2| Z2| M1| E2|   |   ||Z5||                            |
 --   +---------------------------------------------------------------------+


--Peter