Added architecture and design

Also added a note about
  - Reserved MPLS label
  - Reserved VLAN id
  - Reserved multicast address

Change-Id: I86e0c8ed37622bf383ec3d615956f4e0b34f91be
diff --git a/tables/arch-mcast-ingress.csv b/tables/arch-mcast-ingress.csv
new file mode 100644
index 0000000..cb0df50
--- /dev/null
+++ b/tables/arch-mcast-ingress.csv
@@ -0,0 +1,6 @@
+\#,Input,VLAN Table,L3 Multicast Group,L2 Interface Group,Output

+1,None,Set 4094 (\*),Match 4094 (\*) ,Pop VLAN,None

+2,None,Set 200,Match 200,\-,200

+3,200,\-,Match 200,Pop VLAN,None

+4,200,\-,Match 200,\-,200

+5,200,Set 300,Match 300,\-,300
\ No newline at end of file