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A Cisco Telephony Architecture Evolution

Chapter Description

This chapter introduces the concept of ROI, and provides the background and reasoning behind Cisco's decision to migrate to an all-IP network.

Cisco Architecture in the Beginning

The first challenge the team identified was the lack of voice mail integration. Minimizing user discomfort during the migration was of utmost importance, and being able to keep the user's existing phone number and voice mail was high on the "must have" list. "To accommodate this, we came up with a Simple Message Desktop Interface (SMDI) because we knew Selsius supported SMDI," Silva says. "Although they had never used SMDI and had never integrated with Octel, they did have that particular type of interface. So we purchased an Octel 350, dedicated it with a CallManager, and assigned all new employees to this dedicated CallManager." This prevented the necessity of integrating with the PBX and Octel systems.

"Then we decided to put new users on the CallManager software release 2.3 and use the SMDI integration to an Octel 350, under the assumption that we were going to break this system at, say, 500 users," Silva continues. "We had a commitment from the business unit that we could put 500 users on there. However, by the time we got to 500 users, no doubt we'd be on CallManager 3.0, which was the latest software upgrade; we'd have an Octel solution, and all of our problems would be solved."

But like many best-laid plans, that did not happen. The rollout had begun with the first test success, and by the time the team could catch its breath, it was managing 2500 users. "It kind of got out of hand because of Cisco's rapid growth. All new employees were being given IP phones when they started," Silva says. "So here we were with a new system that had never been tested for more than 200 people, and now we had over ten times that."

However, the development team was able to work through the challenges, and with careful monitoring and management of software releases, the initiative to deploy an IP Telephony solution throughout Cisco hit the ground running and never looked back.

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