The binding type of the BFD session.
Options:
1. interfaceIp(1) -BFD for IP with peer-ip and interface
2. peerIp(2) -BFD for IP only with peer-ip
3. sourceIp(3) -BFD for IP with peer-ip and source-ip
4. ifAndSourceIp(4) -BFD for IP with peer-ip, interface and source-ip
5. fec(5) -BFD for FEC(NOT support now)
6. tunnelIf(6) -BFD for Tunnel interface(NOT support now)
7. ospf(7) -BFD for OSPF
8. isis(8) -BFD for ISIS
9. ldpLsp(9) -BFD for LDP-LSP
10. staticLsp(10) -BFD for static LSP
11. teLsp(11) -BFD for TE-LSP
12. teTunnel(12) -BFD for TE-Tunnel
13. pw(13) -BFD for PW;
14. vsiPw(15) -BFD for VSI PW
15. ldpTunnel(21) -BFD for LDP-Tunnel
16. bgpTunnel(22) -BFD for BGP-Tunnel