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At the same time, new network-enabled intranet applications and powerful desktop computers are driving an exponential increase in network traffic. As a result, private intranets are experiencing strains in capacity similar to those found in the Internet.
Network designers (of both the Internet and private intranet networks) are searching for a new networking product that can satisfy the ever-increasing need for bandwidth and transmission capacity. With this new product, network designers will build the next-generation networking infrastructure that will scale to new levels of performance and capacity, satisfying the bandwidth needs of Internet and intranet users.
Cisco Systems has anticipated these trends and has responded with the Cisco 12000 gigabit switch routers (GSRs), targeted at scaling Internet and enterprise backbones to speeds of 155 Mbps (OC-3), 622 Mbps (OC-12) and 2.4 Gbps (OC-48). The GSR offers powerful and distinctive capabilities:
Scalable bandwidth---Supports high-density and high-speed Packet-over-Synchronous Optical Network (SONET) (OC-3/Synchronous Transport Module Level [STM-1], OC-12/STM-4, OC-48/STM-16), and includes high-speed Asynchronous Transfer Mode (ATM) (OC-3/STM-1, OC-12/STM-4).
Scalable performance---Providing multigigabit bandwidth switching capacity of IP datagrams, ranging from 5 to 60 Gbps.
Scalable services---Providing sophisticated congestion management, multicast, and Quality of Service (QoS) features.
The carrier-class design offers Network Equipment Building Systems (NEBS) compliance, extensive SONET/Synchronous Digital Hierarchy (SDH) integration, and all hotswap features to minimize service disruption when removing, adding, or replacing system components.
Most broadband networking infrastructures are based on three broadband networking technologies: SONET, SDH, and ATM. The first GSR release supports line cards that connect the GSR directly to all of these broadband networks.
The four-port Packet-over-SONET/SDH (POS) OC-3/STM-1 line card and one-port POS OC-12/STM-4 line card transmit IP packets directly over SONET/SDH-based optical interfaces at wire speed. The part numbers for these line cards are:
Packet-over-SONET/SDH is a standard based (RFC 1619 and 1662) transmission method that enables the Cisco 12000 to send native IP packets across standard SONET/SDH transmission equipment. An Internet service provider (ISP) or enterprise network designer can attach the Cisco 12000 directly to a high-speed, fiber-based infrastructure. This infrastructure can use either private fiber (dark fiber) or SONET/SDH-based Add Drop Multiplexers (ADMs). With Packet-over-SONET, an ISP or enterprise network designer can scale the speed of its interconnecting SONET/SDH links without experiencing the overhead tax associated with other transmission methods.
The line cards take advantage of the fail-safe features provided by SONET networks by supporting automatic protection switching (APS), defined in the SONET/SDH standard.
Packet data is encapsulated through use of the Point-to-Point Protocol (PPP) and is mapped directly into one of two forms: the STS-3c/STM-1 (for the OC-3/STM-1 version) or the STS-12c/STM-4 (for the OC-12/STM-4 version). These methods comply with RFC 1619, PPP over SONET/SDH, and RFC 1662, PPP in HDLC-like Framing.
With the Packet-over-SONET/SDH line card, the Cisco 12000 can exchange packets with Cisco 7000 family routers using the Packet OC-3 interface processor. This line card is standards compliant and compatible with all leading SONET ADMs.
| Features | Benefits |
|---|---|
| ASIC-Based Queuing and WFQ | Delivers scalable and service-rich software, providing high-performance Layer 3 queuing and traffic engineering capabilities to support IP QoS offerings |
| QoS Support IP-Based Congestion Management (WRED, RED) | QoS/CoS mechanisms enable traffic engineering to increase network utilization and provide the basis for offering differential class of service models and a more profitable operating environment |
| Hot-Swap SONET-Based Redundancy (APS) | Enables SONET/SDH resiliency capabilities to be extended to the Cisco 12000 |
| Single-Mode Line Card that Complies with Bellcore GR-253 Intermediate Reach Specification | Ensures SONET/SDH interface to add-drop-multiplexer (ADM) for multivendor solution |
| 32-MB Packet Buffer Memory Expandable to 128 MB | Maximizes TCP/IP throughput by providing Roundtrip transit times Bandwidth products (RTTxBW) |
| Forwarding Table can Accommodate up to One Million Forwarding Entries | Allows for phenomenal growth, well beyond the 50,000 route entries found today in the Internet |
| Transceiver | Power Budget | Transmit Power | Receive Power | Maximum Distance |
|---|---|---|---|---|
| Single Mode Intermediate Reach | 16 dB | -15 to -8 dBm @1270 to 1380 nm | -31 to -8 dBm
| 15 Km |
| Multimode LED | 11.5 dB | -18.5 to-14 dBm @ 1270 to1380 nm | -30 to -14 dBm
| 2 Km
|
| Transceiver | Power Budget | Transmit Power | Receive Power | Maximum Distance |
|---|---|---|---|---|
| Single Mode Intermediate Reach | 13 dB | -15 to -8 dBm @1270 to 1380 nm | -28 to -8 dBm
| 13 Km |
| Multimode LED | 6 dB | -20 to-14 dBm @ 1270 to1380 nm | -26 to -14 dBm
| 1 Km
|
Posted: Fri Mar 12 01:47:34 PST 1999
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