AudioCodes Media Pack MP-124, User Manual

Page: 131 / 584

Version 6.6 131 MP-11x & MP-124
User's Manual 12. Security
12 Security
This section describes the VoIP security-related configuration.
12.1 Configuring Firewall Settings
The device provides an internal firewall that enables you to configure network traffic
filtering rules (
access list ). You can add up to 50 firewall rules. The access list offers the
following firewall possibilities:

Block traffic from known malicious sources

Allow traffic only from known "friendly" sources, and block all other traffic

Mix allowed and blocked network sources

Limit traffic to a user-defined rate (blocking the excess)

Limit traffic to specific protocols, and specific port ranges on the device
For each packet received on the network interface, the table is scanned from top to bottom
until the first matching rule is found. This rule can either permit (
allow ) or deny ( block ) the
packet. Once a rule in the table is located, subsequent rules further down the table are
ignored. If the end of the table is reached without a match, the packet is accepted.
Notes:
•
This firewall applies to a very low-level network layer and overrides your
other security-related configuration. Thus, if you have configured higher-
level security features (e.g., on the Application level), you must also
configure firewall rules to permit this necessary traffic. For example, if
you have configured IP addresses to access the Web and Telnet
interfaces in the Web Access List (see 'Configuring Web and Telnet
Access List' on page
Error! Bookmark not defined. ), you must
configure a firewall rule that permits traffic from these IP addresses.
•
Only Security Administrator users or Master users can configure firewall
rules.
•
Setting the 'Prefix Length' field to 0 means that the rule applies to all
packets, regardless of the defined IP address in the 'Source IP' field.
Therefore, it is highly recommended to set this parameter to a value
other than 0.
•
It is recommended to add a rule at the end of your table that blocks all
traffic and to add firewall rules above it that allow required traffic (with
bandwidth limitations). To block all traffic, use the following firewall rule:
- Source IP: 0.0.0.0
- Prefix Length: 0 (i.e., rule matches all IP addresses)
- Start Port - End Port: 0-65535
- Protocol:
Any
- Action Upon Match: Block
•
You can also configure the firewall settings using the table ini file
parameter, AccessList (see 'Security Parameters' on page
446 ).