Introduction to IP over SONET:

IP over SONET technology is deployed in IP backbone networks to provide efficient, cost-effective, high-speed transport fast routers. SONET is an ANSI standard which provides rates, formats and optical parameter specifications for optical interfaces ranging from 51 Mb/s to 9.8 Gb/s capacities. SONET provide: Highly survivable/reliable networking because of standardized switching architecture, multivendor inter networking  interoperability standards, and well-thought-out and standardized transport operations and maintenance capabilities. SONET   multiplexing combines low speed digital signals with required overhead to form Synchronous Transport Signal Level One (STS-1).

SONET was providing huge bandwidth, but there was not enough IP traffic to make use of it. Bandwidth can be used fully by mapping IP traffic into higher volume of ATM traffic before transporting it via SONET. ATM is a packet switched technology which can handle both variable-rate traffic and fixed-rate traffic. ATM is based on transmitting all information in small fixed- size packets i.e., 53-bytes long called cells.  ATM is not the most efficient way to transport IP traffic and future demands for bandwidth cannot be met, because it has too much overhead. For this reason users prefer to use ATM when sending audio, video, voice and other IP data types requiring quality of service. So, IP over SONET can carry all types of traffic and is ideal for data-only networks, because it does not use ATM. Thus eliminates a layer of network stack and has lower overhead. All these considerations has become much more important to carriers as volume of IP traffic has increased and ISPs and large corporate users have begun sending IP directly over SONET as fast, cost-effective, reliable, fault tolerant, and easily configurable alternative. 

SONET has following features:

  1. Network management
  2. Protection
  3. Bandwidth Management
  4. Network Simplification
  5. Mid-fiber meet

The problem with IP over SONET is, it uses entire link between the routers, and no other traffic could be multiplexed with the IP packets. Network provider goal is to provide IP transport solutions with low-cost and value- added services: QOS control, guaranteed service availability, and dynamic bandwidth allocation. Since the nature of data being transported over networks change, the demand for IP over SONET is increasing. Because of this increasing demand, network carriers are looking for efficiency and speed that IP over SONET offers. So IP has become dominant internetworking protocol.  Many carriers already have SONET in their network infrastructures, so adopting IP over SONET is a cost effective for them. 

Download  ECE Project Report on IP over SONET .