Martin Walshaw

Quality of Service (QoS)

This chapter describes the approaches for prioritizing. Queuing methods such as priority queuing and custom queuing have their own approaches to moving key traffic to the head of the line. Internet protocol (IP) can enter the fray by enabling its packets marked with higher than normal precedence to get better service. Without explicit configuration, Cisco routers default to either a FIFO basis, or in certain mixes of hardware and software, to weighted fair queuing. This chapter emphasizes that bandwidth is limited, and any opportunity to conserve should be considered. Compression can reduce packet sizes, which can translate into faster transmittal as smaller packets take less time. Compression can place a burden on routers, so one should consider hardware options that offload this task. Routing via protocols such as routing information protocol (RIP) or open shortest path first (OSPF) is usually easy. If not, one can always modify routing behavior using policy based routing and adjusting attributes with route maps. Ultimately, all these tools are designed to give the control needed over the network.

Cisco PIX Firewall

This chapter introduces the Cisco PIX firewalls. This information is useful in determining which firewall is appropriate for requirements. The PIX provides a robust firewall that can protect network from attacks, and can also restrict access to legitimate users and services. The PIX goes beyond its firewall nature by providing additional services such as encryption for data transported across insecure networks and basic intrusion detection. Cisco PIX firewalls can be configured using a number of methods, including commands and web interfaces. Cisco also provides a graphical user interface for accomplishing most configurations. This chapter also provides information that one can use to build a working PIX design, from initial planning to a robust configuration.

IP Addressing, Multicasting, and IPv6

This chapter introduces Internet protocol (IP) version 4 (IPv4) and IP version 6 (IPv6). Regardless of the version used, IP is used to provide logical addressing, and to get the traffic to its destination. IPv4 and IPv6 handle their responsibilities differently, starting with differences in address formats and lengths. Both have special addresses such as multicast that are used in specific situations. IP provides the network layer addressing and functions for the TCP/IP protocol stack. Multicast addresses enable groups of network devices to receive the same datastream, rather than requiring multiple unicast streams. Multicast can be efficient and conserve network bandwidth.

Cisco Technologies, Routers, and Switches

This chapter highlights that the networking has grown from its academic and military origins to become a pervasive factor in the lives of organizations and individuals. The chapter discusses the information needed to deploy and maintain robust networks. The Open System Interconnect (OSI) model is a guidepost for networking, from development to troubleshooting—using its layers can increase effectiveness. Networks can be distinguished by the spatial area that they service. Local area networks (LANs) tend to cover a small area, such as a building or small campus. Wide area networks (WANs) provide the technology necessary to interconnect islands of isolated networks. Cisco provides many solutions that have become integral to networking. LAN switches provide connectivity to end devices such as workstations and servers. Routers are more concerned delivering traffic to its final destination via the use of network addresses such as that provided by Internet protocol (IP). It is important to know and understand the different network technologies, their specific operations, and how they interoperate.

Cisco Voice over IP

This chapter highlights that modern telecommunications have evolved from the advent of the telephone, and many systems are related in some way to the first calls. Initially, analog signaling provided continuous waveforms on which data, including voice, could be transmitted. Digital signaling added compression, error correction and other services to the network. Internet protocol (IP) telephony and IP-based video conferencing solutions present many opportunities to organization, and at the same time introduces an entirely new set of challenges to overcome. IP telephony benefits organization by providing simplified administration, toll bypass, and a unified messaging platform. All of these benefits have the potential to save organization a great deal both administratively and monetarily when implemented correctly. Cisco provides a myriad of hardware and software to enable the transport of voice traffic over non-telephony networks.

Cisco Network Security

This chapter focuses on security for Cisco hardware and software, as well as solutions provided by the same. It also discusses IPsec, which has proven to be a useful and efficient method for securing networks. This chapter reveals that threats to a network can come from someone intending to do harm, or from a malicious source a user inadvertently activates. Both can arise as a result of security policy violations. Threats can compromise the three goals of network security—confidentiality, integrity, and availability. Confidentiality protects information from unauthorized disclosure or intelligible interception by permitting it to be seen only by the intended parties in a conversation. Integrity ensures that information is not altered without authorization or while en route to the authorized receiver. Finally, availability assures that information and services are accessible and functional when needed and authorized.

Wide Area Networking (WAN)

This chapter discusses wide area network (WAN) technologies and topologies. A WAN connects other networks, or groups of networks separated geographically or by organizational design. WAN provides the means for the networks on which those devices reside to reach remote destinations. A WAN can be configured to provide connectivity to any of the end devices; a single server at a distant location can be connected via a WAN to the rest of the organizational network. This chapter provides an overview of WAN technologies provided by Cisco, including their features and salient points. It also provides configuration details for deployment and support of WANs, especially on routers. The chapter also examines to-point connections and their benefit, the related protocols, and a simple point-to point configuration. It describes Frame Relay packets and the fields they contain. Finally, the chapter explains troubleshooting in a Frame Relay environment and the related troubleshooting commands.

Old World Technologies

This chapter provides an introduction to private branch exchange (PBX). PBX-attached phones and services are augmented with Internet Protocol-based telephony and new integrated services, including video, desktop integration, and data services. Many of these functions and offerings are available, and a clear roadmap of what can be availed in the next year is easily identified. However, there are still hurdles to overcome, including reliability and simplicity. It is important to remember that while architecture for voice, video, and integrated data can provide many features in the network and easily replace the modern PBX in many organizations, the hurdles to this convergence include capital costs, support costs, functionality, training, and reliability. A PBX consists of hardware and software designed to emulate the public telephone system within a company and provide paths into the public switched telephone network. These systems can be categorized into four primary areas, each area containing one or more functions: extension termination; trunk termination; system logic and call processing; and switching.

Designing and Implementing Single Site Solutions

This chapter explores the usefulness of Voice over IP (VoIP) and a few architecture for voice, video, and integrated data (AVVID) solutions in a small site environment. It also explores how sites can be designed from scratch and modified from an existing infrastructure. These two options contain many issues of merit, including addressing the usage of mixed vendor network electronics within the same Ethernet network. CallManager is the Internet Protocol (IP) version of private branch exchange systems. A preview of how to install and configure CallManager, how to use it for flexibility purposes when creating and managing IP phones, and how ones mobile users can still benefit from VoIP by using the Cisco IP SoftPhone are provided in the chapter. As VoIP mandates a reasonable return on investment to justify the capital expenses, how one can gain significant ease of administration and flexibility for handling short notice phone changes are discussed in the chapter. How Ciscos AVVID solutions are a boon when distributing information to a large audience by using the IP/TV and IP/VC solutions that can significantly reduce travel expenses and shorten the time to deliver presentations are further explored in the chapter.

AVVID Gateway Selection

This chapter discusses the different types of gateways supported within architecture for voice, video, and integrated data (AVVID) network, looking at the technology from a voice perspective as well as explaining the Internet Protocol/VC 3500 range of products that in simple terms provide H.320 to H.323 conversion. The importance of gateway selection is not to be overlooked, whether the emphasis is on analog or digital protocols or both. Completely understanding all the equipments features and benefits as well as the protocols should help this important decision easier to make. AVVID voice gateways include standalone, IOS-based, and Catalyst switches. The gateway protocols supported are H.323, MGCP, and Skinny with SIP gaining ongoing popularity. The voice gateways range from small analog routers such as the 1750 to large scalable digital T1/E1 7200 routers and everywhere in between. The gateways can be more traditional Voice over IP (VoIP) toll bypass or total integrated all-in-one solutions like the Catalyst 4224.