Content

| 10.2 |  | Introducing Transparent LAN Service Architecture |
| 10.2.2 |  | IP+Optical |

IP+Optical removes the need to layer SONET or ATM technologies between the Layer 3 protocol and the optical physical layer. By removing this additional technology, overhead efficiency is greatly increased.

The Layer 3 protocol is required to provide end-to-end error checking and recovery, as well as any QoS. However, these functions are already built into the IP protocol.

Some of the key benefits to this technology are:

- Efficient transport of time-division multiplexing (TDM), packets, cells, and frames through the reduction of packet overheads
- Services aggregated on Synchronous Transport Signal level 1, basic building block signal of SONET, operating at 51.84 Mbps (nxSTS1) and wavelengths providing for easy manageability and bandwidth management
- Strong QoS and statistical multiplexing of bursty data traffic through existing support in the IP protocol
- Maintains existing Ethernet/IP/MPLS methods as these technologies are not changed at all, merely layered directly onto the optical layer