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Design dtd | User Req | Core | Traffic | Electronics | Router cfg | ISDN | CCNA | Summary

ISDN requirements.

A new site will be brought into the network. This site is small and will only require connectivity from time to time. The decision has been made to connect it into the WAN core network using ISDN technology. Also, you may want to consider a DDR connection to each of the 33 sites in the district, for backup and traffic load purposes. As part of the ISDN configuration and implementation, you need to complete the following tasks:

1. Describe how ISDN will be inserted in the WAN implementation, how data will be sent across the ISDN link, and the benefits of ISDN for a small site.
For ISDN to be inserted into the WAN implementation, either at the one remote site or at all of the sites, three things must be done: ISDN capabilities (router, router configuration, ISDN TA and NT devices) must be in place at the school site; ISDN connectivity must be provided by the telephone company or other provider; and the District WAN core must have ISDN capability (WICs, blades) in its access servers, switches, and routers (though not necessarily directly into the core routers). Data will be sent on a "call" basis. Benefits for a small site include reliability, relatively low cost if it is used intermittently, and fairly universal service compared to other WAN technologies.

2. Document the use of ISDN in the WAN design, including providing the following:
· A drawing of the implementation with all major reference points
Combine TI 5.1.3, graphics 2 and 3, with your school site drawings, your physical topology, and your logical topology from your semester 3 TCS solutions.
· A description of overall bandwidth available to the site and how data communications will take place
Data communications will take place on a "call" basis. Dial-on-Demand Routing will be used; when WAN connectivity is required, the DDR configured router and ISDN devices will place an ISDN "call" and be connected, via the telephone companies' ISDN equipment, to the school district WAN. Costs will include installation, monthly access, and a duration-of-call charge. Bandwidth, for an ISDN BRI line, will be 128 kbps of data over two B channels, and 16 kbps of signaling data over 1 D channel, with much flexibility in how these channels are used.
· A description of all data communications equipment needed to accomplish the implementation
This equipment will depend upon your design. For example, if you use a Cisco 2621 router, you can order WIC modules that have the ISDN NT1 device built in, and you can connect the router directly to the ISDN line. On the District WAN end, the same situation occurs -- it depends on your design. Note that on the District end that if you use DDR to all 33 sites then you will have to handle, via various means, all of that incoming ISDN traffic with a combination of access servers and appropriate routers and/or router modules.

3. Document the router commands needed to implement ISDN on the router and document the resulting changes in the local site access router configurations.
See Semester 4, Chapter 5, TI 5.5.5, graphic 1, for a complete BRI configuration example for the remote site. Of course you will have to change the IP addresses to match those used in your design, and you should add an "encapsulation ppp" to the interface configuration. You will need a similar, but slightly different, configuration for DDR -- see the Web Link in TI 5.6.1.
Include the COMPLETE router configuration, including these changes.

4. Apply the CCNA Certification Exam Learning Objectives to your specific design. This will require a paragraph on how the learning objectives relate to your design. Learning objectives can be grouped together for the purpose of explanation. In this way, you will be studying for their CCNA Certification Exam as you work through the case study.

5. If time permits, try to add a sample DDR lab to the course. This exercise, ties a lot of the material that, up to now, students have only read about. The configuration cookbook at http://www.cisco.com /warp/public /779/ smbiz/ service/configs /async/ async_ip _static_aux.htm gives detailed instructions on why and how to setup DDR configurations. There are tutorials covering the commands used
Washington School District Project Task: ISDN

Now that you should have a firm understanding of the following:
· ISDN provides an integrated voice/data capability that uses the public switched network.
· ISDN components include terminals, TAs, NT devices, and ISDN switches.
· ISDN reference points define logical interfaces between functional groupings, such as TAs and NT1s.
· ISDN is addressed by a suite of ITU-T standards, spanning the physical, data link, and network layers of the OSI reference model.
· The two most common encapsulation choices for ISDN are PPP and HDLC.
· ISDN has many uses, including remote access, remote nodes, and SOHO connectivity.
· There are two ISDN services: BRI and PRI.
· ISDN BRI delivers a total bandwidth of 144 kbps within three separate channels.
· BRI configuration involves the configuration of a BRI interface, an ISDN switch type, and ISDN SPIDs.
· DDR establishes and releases circuit switched connections as needed

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