Upgrading from versions earlier than 9.3.x
You cannot roll forward a configuration directly to this version from BIG-IP version 4.x or from BIG-IP versions 9.0.x through 9.2.x. You must be running software version 9.3.x, 9.4.x, 9.6.x, or 10.x. For details about upgrading to those versions, see the release notes for the associated release.
Release Note: BIG-IP LTM version 10.2.3
http://support.f5.com/kb/en-us/products/big-ip_ltm/releasenotes/product/relnotes-LTM-10-2-3.html
to upgrade 9.2.3 to 9.3.1
Release Note: Local Installation: Upgrading from BIG-IP software versions 9.0.5 through 9.2.5 and 9.3 to BIG-IP software version 9.3.1
http://support.f5.com/kb/en-us/products/big-ip_ltm/releasenotes/local_9_3_1.html
to upgrade from 9.3.1 to 10.2.3
A Upgrading from Versions 9.3.x and 9.4.x and Reformatting for 10.1.x
http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/bigip_getting_started_guide_10_1_0/bip_gs_app_9x_upgrade.html1031015