[j-nsp] logical router - tunnel interfaces

[Juniper]

Hello,

we have a Juniper M20 with a logical division. Two logical routers are 
connected throught 'lt' interfaces. This is the configuration:

lt-0/2/0 {
   
    unit 100 {
        encapsulation frame-relay;
        dlci 100;
        peer-unit 101;
        family inet {
            no-redirects;
            address x.x.x.7/30;
        }
        family iso;
        family inet6 {
            address .../124;
            address .../64;
        }
        family mpls;
    }
}

logical-routers {
    LEVEL3 {
        interfaces {

        lt-0/2/0 {
            unit 101 {
                encapsulation frame-relay;
                dlci 100;
                peer-unit 100;
                family inet {
                    no-redirects;
                    address x.x.x.8/30;
                }
                family iso;
                family inet6 {
                    address .../124;
                    address .../64;
                }
                family mpls;
            }




The other day, I was checking my configuration but in Juniper's website 
I could see in another way:

http://www.juniper.net/techpubs/software/junos/junos83/swconfig83-services/html/tunnel-config20.html

For each connection Juniper uses, one interface with 'encapsulation 
frame-relay' and the other one with 'frame-relay-ccc'.

Which is the correct way to do this interconnection?

Thanks in advance,