Supporting multicast over a network domain

1. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by a Bit Index Explicit Replication (BIER) border router (BBR) of a BIER domain from a Multiprotocol Label Switching (MPLS) domain, MPLS signaling information associated with a point-to-multipoint (P2MP) label switched path (LSP); and

send, by the BBR toward a device configured to assign a BIER tree label (BTL) identifying the P2MP LSP within the BIER domain, the MPLS signaling information associated with the P2MP LSP.

2. The apparatus of claim 1 , wherein the MPLS signaling information is received as Multiprotocol Label Distribution Protocol (mLDP) signaling.

3. The apparatus of claim 1 , wherein the MPLS signaling information includes a forwarding equivalence class (FEC) and an action.

4. The apparatus of claim 1 , wherein the MPLS signaling information is sent in a BIER signaling packet.

5. The apparatus of claim 1 , wherein the device configured to assign the BTL identifying the P2MP LSP within the BIER domain is a controller of the BIER domain or an egress BBR (EBBR) of the BIER domain.

6. The apparatus of claim 1 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

determine, by the BBR, whether the root of the P2MP LSP is located across the BIER domain from the BBR.

7. The apparatus of claim 1 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by the BBR from the device configured to assign the BTL identifying the P2MP LSP within the BIER domain, the BTL identifying the P2MP LSP within the BIER domain; and

configure, by the BBR based on the BTL identifying the P2MP LSP within the BIER domain, an entry indicative of handling of packets of the P2MP LSP within the MPLS domain.

8. The apparatus of claim 7 , wherein the entry indicative of handling of packets of the P2MP LSP within the MPLS domain includes an indication of an MPLS label identifying the P2MP LSP within the MPLS domain.

9. The apparatus of claim 7 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by the BBR via the BIER domain, a packet of the P2MP LSP that includes the BTL identifying the P2MP LSP within the BIER domain;

modify, by the BBR, the packet of the P2MP LSP to replace the BTL identifying the P2MP LSP within the BIER domain with an MPLS label identifying the P2MP LSP within the MPLS domain to provide a modified packet; and

send, by the BBR via the MPLS domain, the modified packet.

10. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by a device associated with a Bit Index Explicit Replication (BIER) domain, Multiprotocol Label Switching (MPLS) signaling information associated with a point-to-multipoint (P2MP) label switched path (LSP); and

assign, by the device based on the MPLS signaling information associated with the P2MP LSP, a BIER tree label (BTL) identifying the P2MP LSP within the BIER domain.

11. The apparatus of claim 10 , wherein the MPLS signaling information is received from an ingress BIER border router (IBBR) of the BIER domain.

12. The apparatus of claim 10 , wherein the MPLS signaling information is received in a BIER signaling packet.

13. The apparatus of claim 10 , wherein the MPLS signaling information includes a forwarding equivalence class (FEC) and an action.

14. The apparatus of claim 10 , wherein the device associated with the BIER domain is a controller of the BIER domain or an egress BIER border router (EBBR) of the BIER domain for the P2MP LSP.

15. The apparatus of claim 10 , wherein the device associated with the BIER domain is a controller of the BIER domain.

16. The apparatus of claim 15 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

send, from the device toward one or more BIER border routers (BBRs) interested in the P2MP LSP, the BTL identifying the P2MP LSP within the BIER domain.

17. The apparatus of claim 16 , wherein the one or more BBRs interested in the P2MP LSP include an ingress BBR (IBBR) from which the MPLS signaling information is received and an egress BBR (EBBR) of the BIER domain for the P2MP LSP.

18. The apparatus of claim 10 , wherein the device associated with the BIER domain is an egress BIER border router (EBBR) of the BIER domain for the P2MP LSP.

19. The apparatus of claim 18 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

send, from the device toward a controller of the BIER domain, the BTL identifying the P2MP LSP within the BIER domain.

20. The apparatus of claim 18 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

assign, by the device, an MPLS label identifying the P2MP LSP within an MPLS domain; and

send, by the device toward a root of the P2MP LSP via the MPLS domain, the MPLS label identifying the P2MP LSP within the MPLS domain.

21. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

obtain, by a Bit Index Explicit Replication (BIER) border router (BBR) of a BIER domain, a BIER tree label (BTL) identifying a point-to-multipoint (P2MP) label switched path (LSP) within the BIER domain.

22. The apparatus of claim 21 , wherein, to obtain BTL identifying the P2MP LSP within the BIER domain, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by the device from a controller of the BIER domain, the BTL identifying the P2MP LSP within the BIER domain.

23. The apparatus of claim 21 , wherein, to obtain the BTL identifying the P2MP LSP within the BIER domain, the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

receive, by the device from an ingress BBR of the BIER domain, MPLS signaling information including a forwarding equivalence class (FEC) associated with the P2MP LSP; and

assign, by the device based on the FEC associated with the P2MP LSP, the BTL identifying the P2MP LSP within the BIER domain.

24. The apparatus of claim 23 , wherein the FEC associated with the P2MP LSP is received in a BIER signaling packet.

25. The apparatus of claim 23 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

send, by the device toward a controller of the BIER domain, the BTL identifying the P2MP LSP within the BIER domain.

26. The apparatus of claim 23 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least:

send, by the device toward the IBBR of the BIER domain, the BTL identifying the P2MP LSP within the BIER domain.

27. The apparatus of claim 26 , wherein the BTL identifying the P2MP LSP within the BIER domain is sent based on at least one of a Multiprotocol-Border Gateway Protocol (MP-BGP) adjacency, a BGP Multicast Virtual Private Network (MVPN), or Segment Routing-Traffic Engineering (SR-TE).