radius irule for IPV6

it looks like whatever is being returned is binary and not a string. Two tangential recommendations as well:

1. Don't use global variables, they demote all connections on that virtual server from CMP. Instead, convert ::attr_code2name to a static namespace variable: static::attr_code2name.
2. Check to make sure the avp is present before acting on it like so:

set CALLID [RADIUS::avp 31 string]
if { not ($CALLID equals "") } {
    persist uie $CALLID 900
    }
}