| For corporate users, the most obvious benefit of IP telephony is cost reduction. Conventionally, a company that has offices nationwide has to pay an enormous amount in fees for external calls between offices, or use costly leased lines. With IP telephony, it becomes possible to make an unlimited number of calls for free, regardless of distance, via your corporate WAN or service provider's IP network. You can also make calls to external parties' IP phones or general subscriber phones at discount rates if they subscribe to the same provider. |
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| Another major benefit is that, if IP telephony is fully introduced, existing analog phone equipment becomes unnecessary and it becomes possible to cut costs for maintenance of PBX, phone lines, etc. For example, when changing the layout of an office due to organizational changes, analog phone systems require that new phone lines be laid and extension numbers be changed. It is costly to contract out setup of phone lines and PBX to specialized vendors. On the other hand, in the case of IP telephony, you can use existing Ethernet facilities such as office LANs. Wiring is simple because phones and computers can share Ethernet cables. Information system personnel can adjust IP-PBX settings. In this way, IP telephony solutions allow companies to substantially reduce both call fees and operation/maintenance costs. |
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QoS functionality supports speech quality of IP phones
As IP telephony infrastructure, an IP network carries voice, email, and various application data. When traffic is dense, the network's transmission speed may slow down or become unstable, which in turn could lead to critical defects such as deterioration of audio quality, delays, or interruptions in voice communications, where real-time transmission is required, even if email and Web functionality are not seriously affected. To prevent such problems, QoS (Quality of Service) functionality plays a significant role in maintaining the quality of IP telephony. QoS controls network bandwidth use for voice, data, etc., based on the necessary size and priority. By reserving bandwidth for IP phones, it is possible to ensure stable voice communications even if a high-volume burst of data is sent or received.
Hitachi Cable's Apresia series L2/L3 switches provide QoS along with high-end functionality and reliability at remarkably low prices. These high-performance switches have been adopted in the IP telephony system of Tokyo Gas and other wide-area Ethernet networks, and contribute to widespread use of enterprise IP solutions. |
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