APDH, SDH, SONET, DWDM & OTN Networks profit from IP based DCN using ITU G.7712

The Problem: OSI and/or IP - OSPF and/or IS-IS

Many of our SONET/SDH, DWDM and backbone router equipment vendors and service provider customers are in the middle of a migration between TMN/OSI based and IP based communication for network management. 

The newer carrier equipment uses IP based management. IP based management is seen as a way to reduce the cost of managing SONET/SDH equipment because an IP-based DCN has lower OPEX and data communication staff is often trained to use IP.

Next to the migration from transport protocol of the DCN, there is also a change in the routing protocol.
Enterprise IP networks use the OSPF protocol, where carrier grade SDH networks use IS-IS (IS-IS is easy to extend with new features) and Internet backbone routers use Integrated IS-IS & BGP. 

There is however a huge installed base of OSI based and IS-IS based equipment. Any migration strategy need to ensure backward compatibility because an upgrade of the whole network is not always feasible and overlay networks is expensive and complex. Telecoms management data networks are large and complex, producing a stable and scalable DCN is hard. An incremental approach to this network upgrade is required. 

Now there is a solution: the new standard ITU-T G.7712

G.7712 is the new standard for the Architecture and Specification of the DCN, supported by the ITU-T and the IETF that applies to PDH, SDH, SONET, DWDM and OTN networks, and supports:

• OSI, IPv4 and IPv6 protocols.

• Backward compatible with the OSI installed base. 

• Key functional elements:

  • Encapsulation of one protocol within another. 

  • Integrated IS-IS protocol. 

• IP and CLNP forwarding

• Integrated IS-IS for routing IP & CLNP

• LAPD and PPP for serial links e.g. DCC

• Automatic encapsulation

  • allows IP traffic to cross legacy OSI DCN

  •  allows OSI traffic to cross new IP DCN

• GRE encapsulation

  • IP/GRE/CLNP & CLNP/GRE/IP

The Vertel software products ETS-IS, ETS-DCC and ETS-LAN can now be ordered with enhancements to support G.7712:

• Integrated IS-IS extensions.

• IP routing and OSI routing

• Automatic encapsulation IP/GRE/CLNP and CLNP/GRE/IP.

• PPP and LAPD data link layer protocols