Information Technology Reference
In-Depth Information
AT M
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Cable
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Digital subscriber line (DSL)
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Wireless
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Chapter 6, “WAN Technologies,” and Chapter 7, “WAN Design,” cover these WAN tech-
nologies. Routers in the enterprise WAN provide WAN access, QoS, routing, redundancy,
and access control to the WAN. Of these WAN technologies, MPLS is the most popular
WA N t e c h n o l o g y u s e d t o d a y. F o r M P L S n e t w o r k s , t h e WA N r o u t e r s p r i o r i t i z e I P p a c k e t s
based on configured differentiated services code point (DSCP) values to use one of sev-
eral MPLS QoS levels. Figure 2-11 shows the WAN module connecting to the Frame Relay
SP edge. The enterprise edge routers in the WAN module connect to the SP's Frame Relay
switches.
Enterprise
Edge
SP Edge
Frame Relay
Network
Campus
Infrastructure
Figure 2-11
WA N M o d u l e
Use the following guidelines when designing the enterprise edge:
Determine the connection needed to connect the corporate network to the Internet.
These connections are assigned to the Internet connectivity module.
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Create the e-commerce module for customers and partners that require Internet ac-
cess to business and database applications.
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Design the remote access/VPN module for VPN access to the internal network from
the Internet. Implement the security policy and configure authentication and authori-
zation parameters.
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Assign the edge sections that have permanent connections to remote branch offices.
Assign these to the WAN, metro-area network (MAN), and VPN module.
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Service Provider Edge Module
The SP edge module, shown in Figure 2-12, consists of SP edge services such as the
follow ing:
Internet services
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PSTN services
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WA N s e r v i c e s
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