RE: [802.3ae] Wan Interface Sublayer
> From: Tom Alexander [mailto:Tom_Alexander@xxxxxxxxxxxxxx]
> Sent: Friday, August 24, 2001 11:00 AM
> I echo James' response. The objective for the WIS was Path
> transparency
> (not Section and Line transparency). Therefore, the WIS SPE
> data rate is
> compatible, the clock tolerance meets SONET Minimum Clock
> requirements,
> and the WIS SPE is formatted properly, with the necessary
> Path Overhead
> functionality. This greatly simplifies the so-called ELTE
> (see T1X1.5/2001-095),
> reducing it to a straightforward Path relay function. There
> was no intent to
> allow a 10GBASE-W interface to be connected optically to an OC-192c
> interface.
Gotcha. Enlightenment is imminent. A few more thoughts and
questions.
It seems to me that the need for an ELTE means that WIS and SONET
networks must remain separated. This being the case, I don't see a general
use for WIS. In other words, I see WIS as useful to do this:
_____
____/ \____
__/ \
/ SONET \_
+---> | cloud \ <---+
| \_____ ____/ |
| \_________/ |
+--+---+ +--+---+
| ELTE | | ELTE |
+--+---+ +--+---+
| |
+------+---------+ +--------+-------+
| W | | W |
| | | |
| 802.3ae switch | | 802.3ae switch |
| | | |
| R R R | | R R R |
+-+-----+-----+--+ +-+-----+-----+--+
| | | | | |
| | | | | |
+-+-+ +-+-+ +-+-+ +-+-+ +-+-+ +-+-+
| A | | B | | C | | D | | E | | F |
+---+ +---+ +-+-+ +-+-+ +-+-+ +-+-+
But I do not see any other reason for WIS usage, since it requires
more parts (and therefore cost, and power) and has a slower data rate than
its R counterparts. Am I missing something here?
/|/|ike