Information Technology Reference
In-Depth Information
or fiber media may be influenced by the environmental or distance requirements. The fol-
lowing sections show some sample LAN types. Table 3-8 summarizes the different appli-
cation types.
Ta b l e 3 - 8
Application Types
Application Type
Description
Peer to peer
Includes instant messaging, file sharing, IP phone calls, and video-
conferencing.
Client-local servers
Servers are located in the same segment as the clients or close by,
normally on the same LAN. With 80/20 workgroup rule, 80% of
traffic is local, 20% not local.
Client/server farms
Mail, server, file, and database servers. Access is fast, reliable, and
controlled.
Client-enterprise edge
servers
External servers such as Simple Mail Transfer Protocol (SMTP), web,
public servers, and e-commerce.
There is a wide range of network requirements for applications depending on the applica-
tion types. Networks today are switched and not shared. Server farms require high-capac-
ity links to the servers and redundant connections on the network to provide high
availability. Costs are lower for peer-to-peer applications and become higher for applica-
tions that traverse the network with high redundancy. Table 3-9 summarizes network re-
quirements for applications.
Ta b l e 3 - 9
Network Requirements for Application Types
Requirement
Peer to
Peer
Client-Local
Servers
Client/Server
Farm
Client-Enterprise Edge
Services
Connectivity
type
Switched
Switched
Switched
Switched
Throughput
required
Medium to
high
Medium
High
Medium
Availabilit y
Low to
high
Medium
High
High
Network costs
Low to
medium
Medium
High
Medium
Best Practices for Hierarchical Layers
Each layer of the hierarchical architecture contains special considerations. The following
sections describe best practices for each of the three layers of the hierarchical architec-
ture: access, distribution, and core.
Key
To p i c
