how i can update Asterisk11.17 to 11.20

[mohamed84]

how i can update astrisk 11.17 to 11.20
i have system down but i taked backup
when restore backup show warning
Asterisk 11.17.1-1 restore 11.20.0-1
DAHDI 2.10.0.1-3 Restore 2.10.2-0
Wanpipe-util 7.0.12-3 restore 7.0.17-22
Freepbx 2.11.0-19 restore 2.11.0-22
Elastix A2billing 1.9.4-5 restore 2.1.0-1

i update freebpx it working but when update other astrisk rpm


warning: asterisk-11.20.0-0.i386.rpm: Header V3 DSA signature: NOKEY, key ID d05 c057c
error: Failed dependencies:
libsrtp.so.1 is needed by asterisk-11.20.0-0.i386
asterisk-addons < 2009020507:11.20.0 conflicts with asterisk-11.20.0-0.i 386
asterisk = 2009020507:11.17.1 is needed by (installed) asterisk-devel-11

please help me