Case Study: Introduction

Case Study Introduction

The case studies for this book use a fictional international company with offices in six locations, as shown in Figure 1-7. Each office has a different set of equipment and network connections to demonstrate the various technologies mentioned in this book. Every location communicates with the others over a Multiprotocol Label Switching (MPLS) network that the ISP manages. A centralized CallManager in the New York office controls phones in Miami, Boise, Shanghai, and Leeds. The Lima voice gateway router is running CME for its phones. Boise has analog phones, Shanghai has a combination of IP and analog, and the other sites have IP phones.

Figure 1-7. Complete Case Study Network

Table 1-1 lists each site and the composition of its voice network. It shows the number of IP and analog phones, the phone number range, the type of hardware, and the IP addressing scheme. You might find it helpful to refer back to this table as you read through the remaining case studies in this book.

Table 1-1. Description of Case Study Sites

Site	Number and Type of Phones	Telephone Number Range	Hardware/Connections	Cisco CallManager IP Range	Data IP Subnet	Voice IP Subnet
New York City, New York, USA	1000 IP phones	1-212-555-2100 through 3499	CallManager cluster 6500 switch with a Communication Media Module (CMM) connected to three T1 PRIs A voice gateway router connected to a PBX via two T1 PRIs	10.1.10.10-20/24	10.1.25-49.0/24	10.1.50-75.0/24
Miami, Florida, USA	50 IP phones	1-305-555-0100 through 0199	Voice gateway router with SRST and one T1 CAS connection to the PSTN	N/A	10.10.25.0/24	10.10.50.0/24
Boise, Idaho, USA	10 analog phones	1-208-555-0100 through 0199	Voice gateway router with three E&M connections to a PBX and one T1 PRI connection to the PSTN	N/A	10.20.25.0/24	10.20.50.0/24
Shanghai, China	200 phones in a combination of IP and analog	86-21-5555-4100 through 4399	Voice gateway router with SRST, two E1 PRI links to the PSTN, and one E1 PRI connection to a PBX	N/A	10.30.25.0/24	10.30.50.0/24
Leeds, England	100 IP phones	44-0113-496-0300 through 0499	Voice gateway router with SRST and one E1 R2 connection to the PSTN	N/A	10.40.25.0/24	10.40.50.0/24
Lima, Peru	18 IP phones	51-1-555-6200 through 6299	Voice gateway router with CME and four BRI connections to the PSTN	N/A	10.50.25.0/24	10.50.50.0/24