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Cisco 7300 Series Routers

Cisco 7300 Series Internet Router Solutions Guide


Solutions Guide

Cisco 7300 Internet Router

Solutions Guide and Reference Architecture


The Cisco 7300 Internet Router is a new mid-range IP optical router. It features high performance, a small form factor, it is modular and price/performance optimized. It has a rich and evolving, software upgradable, set of high performance IP services via the Cisco developed Parallel eXpress Forwarding (PXF) technology, as well as multiprotocol support and additional IP services via the route processor. The hardware is ready for future high availability support which will be enabled through software upgrade.

This document gives a product overview and describes some of the most important applications for the Cisco 7300. As the Cisco 7300 develops with more interfaces and more IP services implemented in PXF, this router will serve numerous application areas. The applicatoin areas described in this solutions gude, are some of the areas where the Cisco 7300 is an optimal choice of routing platform with it's current set of features and interfaces.

Cisco 7300 Overview

The Cisco 7300 is a compact (4RU), high-performance (3.5 Mpps, 4 Gbps point-to-point connections to each line card slot) general-purpose router. It has a NEBS-3 compliant chassis and front-to-back airflow, features ideal for a high-density rack environment.

The Cisco 7300 consists of a six-slot chassis where a processor module, the NSE-100, is required in the lower two slots, leaving four slots for linecards, allowing for a maximum of four linecards for WAN connections. Optionally a second NSE-100 can be installed in the middle two slots, leaving two slots for a maximum of two linecards (post FCS).

The NSE-100 has two fixed Gigabit Ethernet interfaces (GBIC) and an FE connection for out-of-band management. With redundant NSE-100s (post FCS), all four Gigabit Ethernet interfaces can be deployed.

Forwarding is based on PXF technology, where processor intensive IP services applied to the majority of the traffic flows, can be accelerated for optimal performance. A rich set of IP features is currently available in PXF, with more features evolving over time. Multiprotocol (AppleTalk, IPX, DLSw, SNA switching, etc.) as well as control plane protocols (BGP, OSPF, CDP, SNMP, etc.) are supported on the Route Processor, a 350MHz R7000A, which runs standard Cisco IOS® Software.

Cisco 7300 PXF features

The secret behind the high forwarding performance of the Cisco 7300, is the PXF processor. The PXF microcode is very hardware dependent, to achieve the most optimal performance for the platform. Therefore PXF features will be developed over time.

The following are the PXF features currently available and on the roadmap.

  • Cisco Express Forwarding (CEF)

  • Turbo Access Control Lists (ACL)

  • NetFlow version 8

  • Quality of service (QoS) classification and marking

  • Priority queuing

  • Policing (Q1CY02)

  • Network Address Translation (NAT) (Q2CY02)

  • Weighted Random Early Detection (WRED) (Q2CY02)

  • Multiprotocol Label Switching (MPLS) (Q2CY02)

  • MPLS Virtual Private Network (VPN) (Q3CY02)

  • Traffic Shaping (Q3CY02)

Cisco 7300 interfaces

The Cisco 7300 offers interfaces ranging from DS3 through OC-48 speeds. At Layer 2, a wide variety of encapsulations are supported, including Ethernet, Packet over SONET, ATM, HDLC, 802.1Q (Q1CY02) and Frame Relay (Q2CY02).

The following interfaces are currently supported or on the roadmap:

  • Gigabit Ethernet (x 2 on NSE-100)

  • 1 x OC-48 POS

  • 4 x OC-3 POS

  • 6 x T3

  • OC-12 POS

  • 4 x OC-3 ATM (Q2CY02)

  • 6 x E3 (Q3CY02)

  • 1 x OC-48 DPT (Q3CY02)

Mid-Range IP Optical CPE Router

An enterprise will normally have a connection to the Internet via an Internet service provider (ISP) and/or other IP service(s) via a service provider (SP). The connection may be from 32kbps up to as much as OC-48 speeds, depending on need, price, and what is available from the SPs/ISPs operating in the specific areas. Access technologies may vary from plain TDM-based technologies, to ATM and SONET/SDH, connection being a dedicated least line, Permanent Virtual Circuit (PVC) or IP connection to, for example, an MPLS network (see Figure 1).

The Cisco 7300 is an excellent choice for enterprises that require medium- to high-speed connections to the SP/ISP (T3, OC-3 POS, or OC-3 ATM or higher), where IP services are required without any performance degradation

Implementation of services at this point in the network is critical. Typical services required at the edge of the enterprise network facing the SP are ACLs for security, to control access to the network or certain parts of the network and NAT (Q2CY02) to hide the company's IP addresses or translating from private addresses to public addresses. NetFlow allows for traffic monitoring and network planning. QoS features such as classification, marking, queuing, policing (Q1CY02) and shaping (Q3CY02) enable implementing different traffic classes and give different kinds of traffic different priority, depending on the traffic characteristics and QoS policy, and thus allowing the enterprise to optimize the usage of the connection and also conform to the contract with the SP..

Figure 1: Mid-Range IP Optical CPE Router

Midrange IP Optical Enterprise WAN/MAN Router

An enterprise WAN and MAN router is used to connect different sites of an enterprise via a number of WAN or MAN links, their bandwidth depending on the size of the enterprise, as well as the amount of data required to be transported and the connections available. There may also be redundant links as backup in case of failure.

Enterprise networks are commonly arranged as hub-and-spoke topology, as a full or partial mesh between sites or as a ring. Technologies depend on distance, cabling or what's available from the SP in the case where the enterprise does not own its own cables (see Figure 2).

Figure 2: Enterprise WAN/MAN Router

The Cisco 7300 is ideal for connecting sites/campuses of an enterprise connected by WAN or MAN links, where aggregation of a medium number of T3, OC-3 POS, OC-3 ATM (Q2CY02), or OC-12 POS is required. The Cisco 7300 enables densities of up to 4 x OC-3 POS per line card, giving a total number of 16 OC-3s or 24 T3s with Gigabit Ethernet or redundant Gigabit Ethernet to the LAN at each site.

The connection to the LAN is generally via one or two Gigabit Ethernet ports. Redundancy with load balancing over the two Gigabit Ethernet ports can be done on Layer 1 via Gigabit EtherChannel (post FCS), or redundancy and load balancing can be done on Layer 3 with CEF and/or some dynamic routing protocol supporting equal- or unequal-cost load balancing.

Applications for the Small POP

A small Point of Presence (POP) can cover a number of different functional areas, one of which is to aggregate lower-speed links for WAN and metro-aggregation, another of which is hosting servers and services like cache engines and firewalls, and to connect to the core/backbone network, including Internet peering.

These functional areas can be implemented separately or consolidated. The Cisco 7300 is an ideal choice for medium- to high-speed access aggregation and high-speed backbone connections. For lower-speed links, a Cisco 7200 can be used, connecting to a Layer 2 switch together with the other servers present in the POP and connecting to the Cisco 7300 for backbone connection (see Figure 3).

Figure 3: Applications for the Small POP

The Cisco 7300 in this configuration gives performance, up to OC-48 rates for backbone connection, aggregating a moderate number of medium-bandwidth connections (up to 18 T3 or 12 OC-3) with line-rate IP services.

For a small service provider POP, the router must be able to support scalable IP routing and Internet peering. The Cisco 7300 runs full IOS on the Route Processor and hence supports the full suite of routing protocols for which IOS is well known.. It is also critical that IP services can be deployed without performance degradation. In particular, ACLs, NetFlow accounting, and QoS (classification, marking, queuing, and policing (Q1CY02)) are services that are required at the small POP with high performance.


The Cisco 7300 is a high-performance internet router for the optical edge. With interfaces ranging from T3 to OC-48 speeds, it is a great choice for high-speed CPE, connecting the enterprise to the service provider, WAN/MAN aggregation for a moderate number of medium to high bandwidth connections and for the small POP, aggregating WAN links and connecting to the backbone via a high-speed uplink as well as Internet routing/peering. As the Cisco 7300 evolves with more interfaces and PXF featuers, it will fit in numerous application areas.

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