ZyXEL ISG50-PSTN User Guide - Page 29

1.1.3.1 All-in-one Use the ISG50 to provide VoIP and security services. Figure 2 All-in-one Application Scenario Headquarters A LAN Chapter 1 Introducing the ISG50 B DMZ ISG FAX WAN1 C WAN2 ITSP PSTN/ISDN D VoIP Services: • VoIP phones and smartphones can make internal calls and external calls. • Least Cost Routing (LCR) dialing rules put calls through the appropriate outbound line. Long distance calls (to C in the figure) use VoIP and local calls (to D) use PSTN or ISDN. • Auto attendant menu systems act as automatic switchboard operators to help route incoming calls to the proper extension. • Customers (like B) use Web services such as Click To Talk, Skype, or Google Voice to call in. • Voice mail stores voice messages for users and can also forward them by email. • Conference room extensions allow callers from within and outside your organization to join conference calls by dialing a conference room extension. • Use call recording to record all calls for specific extensions or trunks or let users record calls. • VLAN and QoS enhance voice quality. • Fax over IP. • PSTN or ISDN outbound voice trunks and fax service. Security Services: • Firewall protected Internet access and DMZ network for publicly accessible servers. • IPSec VPN-secured VoIP services and internal server access for teleworkers (A and C in the diagram). • Multiple WAN gives fail-over protection for VPN connections and VoIP. 1.1.3.2 DMZ Installation Use the ISG50 with a USG, ZyXEL's Unified Threat Management (UTM) firewall to add more security services like IDP and anti-virus. If you connect the ISG50 to a USG model's DMZ, the ISG50 ISG50 User's Guide 29