With the new Packet OC-3 Interface Processor for Cisco 7500 and 7000/RSP series routers, Cisco offers industry-leading broadband data interface bandwidth to support the most demanding applications across both local-area and wide-area networking environments. -Operating at 155 Mbps, the Packet OC-3 interface provides the highest available interface bandwidth for packet-based traffic and is completely compatible with SONET and Synchronous -Digital Hierarchy (SDH) -network facilities. By using standard packet protocols with -efficient overhead structures, the Packet OC-3 Interface Processor -maximizes data throughput and line utilization for expensive, high-bandwidth facilities.
Highest Available Interface Bandwidth for Packet-Based Traffic
In 1991, Cisco pioneered the packet-based High-Speed Serial Interface (HSSI®) to meet the need for high-speed data transport over 45-Mbps DS-3 facilities. Over the last five years, carriers worldwide have invested heavily in SONET/SDH equipment, making SONET/SDH the most widely deployed broadband networking technology. And over the same period the bandwidth requirements of data applications have grown dramatically. The new Packet OC-3 interface now enables these broadband data applications to efficiently access this extensive -broadband transport infrastructure. Equipped with OC-3 interfaces, packet-based networking equipment can match the interface bandwidths -supported by Asynchronous Transfer Mode (ATM) while providing much higher bandwidth efficiencies.
In wide-area networking applications, the Packet OC-3 interface can directly connect to both carrier and private SONET and SDH facilities. SONET/SDH facilities often provide the most reliable transport, because they can be configured based on dual counter-rotating ring topologies. In local-area networking, Packet OC-3 interfaces can be used to provide direct broadband links between routers in a campus or building without the need for an intermediate switch.
Cisco's Packet OC-3 Interface Processor provides a single OC-3 155-Mbps port and is available with either single-mode or multimode interfaces. Packet data is transported using Point-to-Point Protocol (PPP) and is mapped into the STS-3c/STM-1 frame. The Packet OC-3 interface is compliant with RFC 1619, "PPP over SONET/SDH," and RFC 1662, "PPP in HDLC-like Framing." The encapsulations used apply only seven bytes of transport overhead per frame, which is less than half of that involved with ATM using ATM adaptation layer 5 (AAL5) and line card control (LCC) Subnetwork Access Protocol (SNAP) encapsulations. The Packet OC-3 Interface Processor can operate in any Cisco 7500 series or Cisco 7000 series system equipped with a Route Switch -Processor (RSP). In Cisco 7000 series routers, the Packet OC-3 interface processor can access the -system's CxBus; in Cisco 7500 series systems it can utilize the full -gigabit-per-second bandwidth provided by the Cisco 7500 CyBus.
The Packet OC-3 Interface Processor operates on a version of the Cisco Internetwork Operating System (Cisco IOS) software that will support distributed switching and distributed services capabilities.
- Standards-compliant SONET/SDH interface
- Supports full-duplex operation at 155 Mbps
- Intermediate reach optical interface with single-mode fiber
- Optical interface with multimode fiber
- Supports SONET/STS-3c and SDH/STM-1 framing and signaling overhead
- Online insertion and removal (OIR), enabling users to remove, add, or replace interface processors on line