Datacom > Modems & CSUs

Identity
Accurate and positive identification of network users, hosts, applications, services, and resources is a must. Kerberos, password tools, and protocols such as RADIUS and TACACS+ enable identification.

Perimeter security
This enables you to control access to network applications, data, and services so only authorized users and information can pass through the network.

Data privacy
Data privacy is the providing of confidential data on command to authorized users while protecting that information from eavesdropping or tampering. Tunneling, encryption technologies, and protocols like IPSec provide important protection when implementing Virtual Private Networks (VPNs).

Security monitoring
You also should regularly test and monitor security preparations. By being proactive, you can identify areas of weakness and make adjustments. When a real security event occurs, you’ll be ready.

Policy management
It’s likely your network will grow in size and complexity. You’ll need centralized policy-management tools that use directory services to grow with the network. These tools define, distribute, enforce, and audit the security policy through browser interfaces, plus they enhance the usability and effectiveness of your network’s security solutions.

Security modems typically offer four options for levels of security:
• No security
• Password
• Password with callback
• Password with callback and second-level password

Auto callback enables an answering modem to dial a prestored callback number after answering a call.

When configured for auto callback security, modems like the Series II Modems provide secure and cost-effective corporate LAN access for both travelers and telecommuters. Unauthorized connections are prevented by invalid passwords.

Callback numbers minimize toll charges via the following procedure: When called, the security modem will answer and, after a slight delay, respond with a prompt that requests entry of your modem’s login password. Once you’ve typed it in correctly and hit the return key, the security modem can either allow the user through or disconnect and dial back the prestored number.

The security modem gives you several attempts at each prompt to provide correct information—incorrect entries result in a password retry. If the requested information isn’t provided within a set amount of time, your call is disconnected.

Depending on what security level your particular modem is configured for, you may or may not be asked to provide more password information upon callback.

If the second-level password clearance is required, then the security modem responds with another request for your modem’s login password when your modem answers the callback. After you enter the password, the security modem should respond with an acknowledgement of connection.

This acknowledgement tells you that the modems are now in Data Mode, your reversal of phone charges is complete, and you are ready to communicate with the host computer.