Chapter7.Dial Troubleshooting

Chapter 7. Dial Troubleshooting

The troubleshooting approach in this chapter demonstrates the layer-by-layer and phase-by-phase approach to dial issues. It is important to be systematic and go step-by-step, starting with the physical layer from both ends. Unlike service provider-based remote access solutions, both ends of the connection are available for troubleshooting in an enterprise remote access scenario. This chapter focuses on the following main topics:

• Detailed troubleshooting network access server (NAS) wide-area network (WAN) links, including T1 circuits and PRIs

• Troubleshooting dial-in services

• Troubleshooting dial-out services

• Specific commands and debugs for NAS 5x00 routers, including Cisco 5200, 5300, and 5400

With this chapter, you can enhance your knowledge about T1s and PRIs. This information is relevant to all parts of this book and should be reviewed as necessary. The dial-in and dial-out troubleshooting techniques are explained in detail, from the viewpoint of the NAS, which gives you the best understanding about the nature of the processes. Troubleshooting the modem operational status is demonstrated in great detail. The specifics of the different platforms provided in this chapter should help you to improve your skill set in dial technology.