EVA4400 iSCSI Implementation with MPX200 Router and X3400G2 Network Storage Gateway

[pandirivs]

Hello,
I am new to SAN and this forum also. We are planning to implement SAN solution with iSCSI.
One vendor proposed a solution EVA4400 SAN with MPX200 Routers for iSCSI output. Another vendor proposed a solution EVA4400 with X3400 G2 Network Storage Gateway. I would like to the performance difference between these two implementations. I would be thankful if somebody points me to some location/URL where i can get detailed pros and cons of these two solutions

Thanks in advance

Sankar