tailieunhanh - configuring cisco avvid phần 6

nhiều hệ thống nhắn tin nằm trong cùng tòa nhà, trên cùng một khuôn viên, ở các thành phố khác nhau, hoặc thậm chí ở các nước khác nhau có thể được kết nối với nhau thông qua mạng PSTN. Một giọng nóiĐiện thoại IP Voice Mail tích hợp sử dụng SMDI trong một mạng AVVID | Utilizing AVVID Applications and Software Solutions Chapter 5 171 can support up to 10 000 users. There is a ten-site maximum that can be networked through the WAN. The admission control for distributed call processing is through gatekeepers and distributed call processing allows for transparent alternate routing should a WAN link fail. When using centralized call processing the CallManager and voice messaging services are located at a central site. Centralized call-processing supports up to 2500 users total and a maximum of three CallManagers. All IP phones must be registered to the same CallManager. The downside to a centralized call processing model is that there is no service if the WAN goes down unless there is a dial backup. However this drawback can be accounted for by a thin CallManager that will be able to reside on many Cisco routers. This thin CallManager will be part of Cisco s IOS and will provide rudimentary routing functionality should the WAN and thus the primary centralized CallManagers become unavailable. The Development of CallManager The CallManager was developed as a software-based call-processing component of Cisco s IP Telephony solution. Cisco s CallManager is central to the AVVID distributed architecture. Cisco s CallManager versions and have had been deployed on a limited basis as the support for the product was minimal and did not have a wide breath of integration with the rest of Cisco s product line. The IP phones at the time the SP 12 and the VIP 30 were not at all elegant as are current models and gateway support was limited to a DT-24 card installed in a server or analog gateway devices. With the release of CallManager we see a newly designed Web browser interface. Moreover the new CallManager is installed on a Windows 2000 Media Convergence Server MCS and is no longer sold as a separate software product. In fact the current Cisco CallManager software release checks the Basic Input Output System BIOS of the MCS