Polycom ViewStation EX4000 - Manual (Page 62)

Integrators’ Reference Manual for ViewStation EX, ViewStation FX, and VS4000
52 www.polycom.com
LAN/WAN Considerations
You will need to develop a network topology checklist that includes
the following information:
❑
List of Networks: To take advantage of least cost routing and
alternate routing, you must define the topology of the Local area
networks (LANs) that each gatekeeper serves, as well as the
LANs that are logically connected to these but served by other
gatekeepers. This allows the gatekeeper to determine how IP
traffic is routed from one endpoint to the next. PathNavigator
uses the network topology to determine when resources are
unavailable so that an alternate (ISDN) path can be determined.
❑
Subnets within each network and subnet IP address: A
network address is the equivalent of a subnet. You will need to
define all subnet addresses within your LAN. If this information
is not available to the gatekeeper, calls may be rejected because
no route can be determined.
❑
WAN links: These are logical connections from one LAN to
another LAN within the WAN cloud, or logical connections
from one network to another network outside of the
organization. The two types of WAN links are the dedicated
WAN link, which is a logical connection via a dedicated link,
leased line, frame relay or though an ATM network; and the
WAN link to other networks through a VPN tunnel, which
connects one network to another through a secure connection
over the Internet.
❑
Network Diagram describing how networks are connected and
bandwidth capacity on each WAN link.
Each gatekeeper will need information about its neighbor
gatekeepers to be able to communicate with them. Neighbor
gatekeepers manage other H.323 zones within an organization and
allow the network’s workload to be distributed across logical
boundaries within the organization. This enables more efficient use
of the network by limiting communication between zones (across
WAN links). When a call originates with one gatekeeper's zone and
that zone's gatekeeper is unable to resolve the dialed address, it will
be forwarded to the neighbor gatekeepers for resolution. The port
used for gatekeeper-to-gatekeeper communication is usually 1719.