Polycom 4300T Benutzerhandbuch

 Configuring the 4300T

3 - 3

• NAT/PAT translation for IP phones and PC’s.  This allows a single public 

IP address to be used on the WAN link to represent all of the private IP 

addresses assigned to the LAN IP phones and PC’s.

• Static NAT entries.  This enables the customer to use a WAN public IP 

address for data servers (web, mail, ftp, etc.) connected behind the 4300T.  

These servers can then be configured with private IP addresses for 

additional security.

• A “VoIP” aware firewall.  A full Layer 7 gateway for voice traffic and a 

stateful packet inspection firewall for data traffic.

• Call Admission Control (CAC). CAC uses a deterministic algorithm to 

decide when there are insufficient network resources available to 

adequately support new calls and then return the equivalent of a “fast 

busy” to new call requests. 

• DHCP server and TFTP relay.  These features are used to simplify and 

expedite the IP configuration of phones and PC’s.  This also includes VoIP 

signaling gateway information (MGCP, SIP, H.323 and SCCP).

• Call quality monitoring (using MOS, jitter, latency, packet loss and much 

more) and test tools.

• VoIP survivability.  Provides call switching to an LAN based PSTN 

gateway during WAN outages.

System Configuration

configure LAN/WAN interface

Yes

set ethernet link rate

Optional

enable the DHCP server

Optional but recommended

configure SNMP

Optional

VoIP Configuration

enable the VoIP ALG

Yes

configure a VoIP subnet route

Optional

Data Networking Configuration

dynamic NAT

Optional but recommended

static NAT

Optional

static IP routing

Optional

Firewall Configuration

enable the data firewall

Yes

configure basic settings

Optional

configure advanced settings

Optional