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To access the contents, click the chapter and section titles.
Wireless Networking Handbook
SNMPv1 is a simple request-response protocol offering the following operations:
SNMPv1 is very mature and is highly available, but it has high overhead because each object from the agent requires a separate transfer of data across the network. In addition, SNMPv1 does not incorporate any security features. Therefore, someone can easily spoof a network management station. SNMPv2 is just emerging as a replacement to SNMPv1 and offers several advantages. For instance, SNMPv2 has a GetBulkRequest command that provides a transfer of bulk data, reducing the amount of overhead. Also, SNMPv2 supports authentication and encryption to combat spoofing. Identifying ProductsAfter you have defined the technologies necessary to support network requirements, you need to identify appropriate products. In some cases, such as the NOS and applications, you might have already selected the product as part of the network element definition phase. Regardless, select all products and materials necessary for implementing the network and create a bill of materials. In general, select products based on the following criteria:
The following criteria are also important when selecting wireless products:
Identifying the Location of Access PointsMost environments, such as hospitals, factories, and warehouses, cover an area exceeding the range of wireless LAN devices. As described in Chapter 2, wireless LAN vendors sell wireless local bridges (often called access points) to provide an interface between wireless users and wireline technologies such as IEEE 802.3 ethernet or IEEE 802.5 token ring. In addition, most of these access points also support wireless users who roam from one cell to another. A major design concern is identifying the location of these access points to provide an interface to network resources located on wired networks and to provide adequate coverage for roaming users throughout the facility. It would be easy to deploy a wireless network in a completely open area, free from obstacles like walls, desks, and window blinds. This would allow radio waves from the wireless devices to maintain an omnidirectional radiation pattern, making it simpler to predict the maximum operating range between all devices and the locations of the access points. The presence of objects and the construction of the facility, however, causes attenuation to radio wave signals that distorts the radio propagation pattern, making it difficult, if not impossible, to predict. Table 8.1 gives you an idea of the degree of attenuation of various types of RF barriers.
When establishing requirements for the network, review the environment (see Chapter 6, Defining Requirements for Wireless Networks) to give you enough information to select the appropriate type of wireless medium. To identify the location of access points, though, you need to evaluate the environment to a much higher level of detail, especially the effects of the environment on propagation of radio waves. The best method for identifying the location of access points is to perform an RF site survey. Start by obtaining the following items:
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