SunComm Technology
SunComm Technology Co. Ltd. (Chinese: 相光科股份有限公司; pinyin: Xiāngguāngkē Gǔfèn Yǒuxiàn Gōngsī) is a Taiwan multinational computer technology and GSM Voice over IP gateway manufacturer. The main products in 2010 focused on GSM VoIP gateways & IP surveillance camera devices. Core members have been engaging in the communication & networks industry since 1977.[citation needed] HistorySunComm Technology Co., Ltd (Chinese: 相光科技) Operations Dongguan, China Liaison Office has
been set up at Guan-Dong Province to provide service from Taiwan and China. Wifi IP Phone
gateway 2, 4, 6, 8, 16, 24 ports
GSM Gateway (FWT) ProductsA VoIP phone has the following hardware components:
Other devices
There are several Wi-Fi enabled mobile phones and PDAs that come pre-loaded with SIP clients, or are capable of running IP telephony clients. Some VoIP phones also support PSTN phone lines directly. Another type of gateway device acts as a simple GSM base station and regular mobile phones can connect to this and make VoIP calls. While a license is required to run one of these in most countries these can be useful on ships or remote areas where a low-powered gateway transmitting on unused frequencies is likely to go unnoticed. 
Disadvantages of VoIP phones IP networks, particularly residential Internet connections, are easily congested. This can cause poorer voice quality or the call to be dropped completely. VoIP phones, like other network devices can be subjected to denial-of-service attacks as well as other attacks, especially if the device is given a public IP address. Due to the latency induced by protocol overhead they do not work as well on satellite Internet and other high-latency Internet connections. Requires Internet access to make calls outside the local area network (LAN) unless a compatible local PBX is available to handle calls to and from outside lines. VoIP phones and routers depend on mains electricity for power, unlike PSTN phones, which are supplied with power from the telephone exchange. However, this can be mitigated by installing a UPS. See also
References
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