Device Interface
Polycom, Inc.
15
In addition to being a NAT (Network Address Translation) router, the HDA50 includes a DHCP server, a DNS
forwarder, and a basic firewall. It supports port forwarding, DMZ, QoS, and VLAN (802.1Q). The maximum
routing throughput between the WAN and the LAN side is approximately 30 Mbps. This speed can be
achieved when there are no active calls in the system. Otherwise, speed is limited to accommodate the
voice processing load. If the WAN side is connected to an Internet access device, the speed could be further
limited by the Internet uplink and downlink.
The HDA50 acquires its WAN side IP address using one of the following methods:
●
Static Address Assignment
●
DHCP
●
PPPoE
The HDA50 acquires its WAN side IP address using DHCP by default. Also by default, the HDA50’s own
DHCP server is enabled to support LAN side clients such as PCs. The default LAN side IP address of the
router is 192.168.10.1.
Incoming packets received from the WAN side are forwarded by the router according to the following flow:
●
If the firewall is enabled, discard the packet if it’s rejected by any one of the active firewall
components.
●
If the sending host address matches a valid entry in an internal host binding table, queue the packet
for local processing. The router updates the binding table.
●
If the sending host address matches a valid entry in an internal NAT binding table, forward the packet
to the corresponding LAN IP address. The router updates the NAT binding table.
●
If the receiving port and protocol match a reserved pair to support an internal process, queue the
packet for local processing.
●
If the receiving port and protocol match a port forwarding rule, forward the packet to the LAN IP
address according to that rule.
●
If a DMZ host is configured, forward the packet to that LAN IP address.
●
Queue the packet for internal processing.
DHCP Server
By default, the built-in DHCP server is enabled on the HDA50. It assigns IP address, network mask, DNS
server, and default gateway address to the DHCP clients on the LAN side. The default gateway and DNS
server have the same IP address as the LAN side IP address of the router. In the DHCP server configuration,
you can select the range of client IP addresses to give out the Lease Time and the Local Domain Name.
Furthermore, by using the DHCP reservation feature, you can reserve specific IP addresses for some
devices with specific MAC addresses. See the
sections for more details.
Firewall
The firewall protects local processes and LAN side clients against certain basic threats from the WAN side
(or the Internet), such as port scanning and a DOS (Denial of Service) attack. Use the firewall settings to
turn on or off the following features:
● NATRedirection
– If enabled, supports NAT Redirection, also known as NAT Loopback or Hairpin.
The default is disabled.
● DRDOSAttackProtection
– If enabled, protects against DOS attack. The default is disabled.
