Can the SSO/NSF redundancy mode be used as a replacement for SSO/SRM for SUP720-3Bs. I need to use 12.2(18)SXD because of its support for the WLSM, but as of 12.2(18)SXD, the redundancy mode of SRM with SSO is not available. Can NSF with SSO be used as a replacement even though many of the connected routers will not be NSF-aware?