The serctl script has problems on a standard Solaris 8 Install:
 
# serctl ul add 1000 sip:1000@10.10.10.10
grep: illegal option -- E
Usage: grep -hblcnsviw pattern file . . .
sip:1000@10.10.10.10 is not a valid URI
#
It turns out that the normal "grep" command on Solaris does not include the "-E" option.  You have to use /usr/xpg4/bin/grep instead.  I modified the line:
 
check_uri() {
#       echo "$1" | grep -E "^sip:([a-zA-Z0-9_]+@)?.*\..*"
        echo "$1" |  /usr/xpg4/bin/grep -E "^sip:([a-zA-Z0-9_]+@)?.*\..*"
and it seems to be working ok.
 
Just though other Solaris users might want to know.
 
Regards,
Ricardo