Which kind of networking should be implemented to provide messaging among all the offices?

Company A is one of the world’s largest brokerage firms. This corporation was founded in 1956 and is known for providing advanced communication services to its brokers, ensuring the fastest and most reliable communication. The company currently has over 10 million customers who trust them for the buying, selling, and trading of mutual funds, stocks, and precious metals.

The Company Headquarters (HQ) is located in Manhattan. It has offices in seven cities in the United
States and five international cities. HQ has 3500 employees. Other U.S. locations include the Chicago office (1200 employees); Miami (450 employees); Boston (820 employees); Dallas (350 employees); Seattle (350 employees); and Los Angeles (1100 employees). International locations include Madrid (300 employees); London (200 employees); Paris (300 employees); Tokyo (450 employees); and Kuala Lumpur (500 employees).

The company uses Cisco routers, switches, firewalls, and intrusion detection, and has installed Cisco Unified CallManager clusters at all locations. The corporate network uses Microsoft Windows 2000 Active Directory.

There are two forests. The first forest has two root domains: coa.com and coa.internal. The second forest root has only one domain: coaasia.com.

There are redundant domain controllers/global catalog servers at each location. DNS and DHCP servers are also found at each location. The HQ site has two OC-48 connections using HSRP. All sites have redundant T3s using HSRP to the HQ along with a T1 to every location, providing a fully meshed architecture. The company uses an Exchange 2000 messaging platform. There are no planned upgrades to Exchange 2003 at this time.

There are two Exchange organizations: Org1 includes all North American and European servers and Org2 includes all Asian servers. Both organizations use a single routing group. Org2 has each city’s Exchange servers in a unique administration group, while Org1 has a single administration group. Each office has local Internet connectivity, and each office maintains its own Exchange servers.

The company just upgraded to Cisco Unified CallManager at all locations. Two MCS 7835 servers are located at each site, except HQ, which has three MCS 7835 servers. There are inter-cluster trunks established between all subscribers in all clusters.

The company likes the ability to route all intra-company calls over their 3DES encrypted network links. The existing voice-messaging platform was provided by several different vendors and there is no networking between them. The company plans to change voice-messaging platforms at all locations to Cisco Unity. The system will initially be voice-mail-only, but will switch to Unified Messaging during the next fiscal year. Cisco Unity servers will be placed in each office.