?eta????a? Crossbar

1
?eta????a? Crossbar
2
?eta????a? Knockout

• ?a??de??µa ??a Crossbar.
• S???e?t??t?? ep??e?e l ap? ta n pa??ta.

e?s?d??
???d??

• ????p????t?ta

3
?eta???? µe µe?????? ?pt????? buffers (Switch
with Large Optical Buffers - SLOB)
a???s?µ?p???ta
e?s?d??
???d??

• ?eta???? µe buffers e??d?? se p???? ep?peda.
• ?s?te???? wavelengths µp????? ?a
  ???s?µ?p???????.
• ????? buffer t?? pa??t??, ?p?? k
  t? p????? t?? ep?p?d??.
• Modular s?ed?asµ??.

4
? Staggering µeta????a?

• ???s?µ????e? ??a µeta????a µe buffers e??d??.
• ??te modular, ??te scalar.
• ?? p????? t?? ??aµµ?? ?a??st???s?? µe?a???e?
  ??aµµ??? µe t? ß???? t?? buffers.
• ??s? µe???? p??pe? ?a ???e? t? b ??a
  ?ata???st??? ?????f???a

5
?pt???? µeta????a? pa??t?? d?aµ???a??µe???
µ??µ?? (Shared Memory Optical Packet Switch -
SMOP)

• ?eta????a? µe d?aµ???a??µe???? buffers e??d??.
• Recirculating-loop µ??µ? µe ?????d??µ?????s?.
• ??? modular.

6
T s??sµ??
e?se???µe??? s??desµ??
?????? (i)
e?e???µe??? s??desµ?? j
i
?????? (l)
l
?????? (j)

• ? s???d?? e??a? (n,T)-?µa?? (smooth), a? µp??e?
  ?a µetad?se? t? p??? n pa??ta se ??a p?a?s??
  (frame) µe?????? T (? µ?s?? ???µ?? e??a? nC/T).
  ??t? ? ?d??t?ta d?at??e?ta? ?a? st??? a?????????
  s??d?sµ???.
• ?s? µe?a??te?? e??a? t? T,
• a. t?s? p?? ?ata???st??? ep?t??peta? ?a e??a? ?
  s???d??.
• ß. t?s? µe?a??te?? e??a? ? e?e????a st?? a???es?
  ???µ??.
• ?. ??s? pe??ss?te?e? ??aµµ?? ?a??st???s??
  ??e?a??µaste.
• G?a ???e s??desµ? p??pe? ?a e?asfa???eta?, ?t?

7
?eta????a? ?????d??µ?????s?? (Scheduling Switch)

• ?a pa??ta p?? eµfa?????ta? ?at? t? d????e?a t??
  ?d?a? s??sµ?? st?? e??d??? t?? ?????d??µ?????t?,
  apa?t??? d?af??et????? e?e???µe???? s??d?sµ???
  t?? crossbar.
• ? t??? t?? pa??t?? d?at??e?ta? ??a ??a ded?µ???
  ?e???? e?s?d??-e??d??.

8
?????d??µ?????t??
MlogT

• ???p??e?ta? µe N pa??????a ??ad?? (branches),
  ??a ??a ???e e?s?d?.
• ???e ??ad? ap?te?e?ta? ap? 2logT-1 µp???
  ?a??st???s??.

9
Benes-?s?d??aµ? d??t??
10
???t?????? e???????? ?????µat??
e?t??p?? (Deflection Virtual Circuit Protocol)
?pa?te?ta? e????st? buffering (apa?a?t?t? ??a
p????? ?pt??? d??t?a) - ??? ap??e?a pa??t?? - ???
e? t?? p??t???? ??at?se?? - ap?? a?ad??ta??
(resequencing).
µ???p?t? t?? de?te??? block
set-up pa??ta
p??t?µ?µe?? µ???p?t?
p???
? s???d?? ?????eta?
µ???p?t? t?? p??t?? block
?? t? set-up pa??t? de? µp??e? ?a a???????se? t?
p??t?µ?µe?? µ???p?t?, ?ata?aµß??e? ??a? ????
e?e???µe?? s??desµ? (µe t??? p??t?µ?s??) ?a? ?
s???d?? e?t??peta?. ?? ?e?? a??µesa st? set-up
pa??t? ?a? st? p??t? pa??t? ded?µ???? p??pe? ?a
e??a? epa???? ??a H e??????? t?? p??????
d??µ?????s??. ?et? ap? H ß?µata ? s???d??
p?fte?.
11
??µß??
s??????? e?se???µe?? ????t???t?ta s???????
e?e???µe?? ????t???t?ta Ctotal
e?se???µe?? s???d??
d?a??s?µ? e?e???µe?? ????t???t?ta
??e???µe?? ????t???t?ta gtr µp??e? p??ta ?a
ß??s?eta?, p??a??tata µe t? ??st?? t?? d?a??p??
s???d?? p?? ????? p??? t?? A. ?? s???d?? p??
d?a??pt??ta?, s??e?????? t? µet?d?s? ?ta? ? p???
??ße? ??a µ???µa ap???????. ??a s???d?? µp??e? ?a
??e?aste? ?a ????ste? se k ?p?s???d??? (?
a?ad??ta?? k µp??? pa??t?? e??a? e?????te?? ap?
t?? a?ad??ta?? a?e???t?t?? pa??t??).