Client Software and Adapter
Any client computer, laptop or wireless device with a compatible wireless client adapter allows connectivity with an access point. The client adapter is a radio transmitter with firmware that supports any of 802.11a/b/g signaling. That is needed before the device can associate and authenticate with the access point. Some access points have a no client mode that doesn’t allow any association from clients extending network distance. Client wireless software included with the adapter must be implemented with specific Windows platforms. The client adapter will be integrated with the laptop, PCMCIA slot or desktop PCI bus slot. They will support specific wireless standards, antenna characteristics, WiFi certification, WDS, network range and security. The wireless manufacturer software must be implemented for all available features. The following is a list of some client adapter configured settings.
Access Point
As the name suggests an access point allows connectivity between the wireless client or wireless device and the wired network. The access point takes wireless data packets from a client and translates them to standard Ethernet data frames before transmitting across the wired network. Standard category 5 twisted pair cabling will connect the access point Ethernet port with a catalyst switch Ethernet port. The maximum distance between access point and network switch is 100 meters standard with Ethernet design.
WLAN Controllers
Wireless designs with hundreds of root access points on an enterprise network will sometimes deploy wireless LAN controllers. The design specifies lightweight access points connecting to a network switch. The 4404 WLAN controller device acts as a hub connecting 4 network switches supporting 100 access points. Cisco wireless control system (WCS) wireless network management software is sometimes deployed with WLAN controller design for planning, configuring and optimizing the network.
Posts Tagged ‘Network Switch’
Wireless Network Components – Basics of Any Wireless Network
January 26th, 2010Network Switch Selection – How to Select a Network Switch
January 1st, 2010
Overview
The network switch is the most common network device implemented with company infrastructure and as such the selection of any new switches or upgrading is a key part of most network design projects. The Cisco network switch components include Switch Chassis, Supervisor Engine, Switching Modules, IOS/CatOS software and Power Supplies. The decision to buy new switches or upgrade equipment will be decided after considering the network assessment and design features specified. Wireless designs, as an example, will have network switches interfacing with access points. That will have an affect on the switch such as increased utilization, assigned switch ports, access control lists, Trunking, Spanning Tree Protocol and increased wattage draw from Power over Ethernet (PoE).
Switch Chassis Features
The Switch Chassis features include – chassis dimensions, number of slots, processor slot assignments, switching fabric, engines types supported, power supplies, rack units needed.
Cisco Supervisor Engine (SE) Features
Cisco switches are implemented with an Engine (Switch Processor) for processing packets on a network segment. Routing is accomplished with an on-board Multi Layer Switch Feature Card (MSFC) or Route Processor running IOS code. The switch Engine running IOS code on the MSFC and the switch processor is in native mode, while those running CatOS on the processor are in hybrid mode. Some engines won’t support native and hybrid mode. The engine with no MSFC supports what is called CatOS mode. Select the engine that matches your design specifications. The MSFC module is integrated with the Engine or upgradeable. You must implement a PFC module with any MSFC. Some Engines have no MSFC module – the routing is integrated with the hardware and as such support native mode only.
The Cisco Supervisor Engine features include – supported chassis, uplink speed, processor memory, native IOS, CatOS, PFC, MSFC, slot assignment, failover.
These are some of the popular Cisco engines and their switching features.
720 – Cisco 6500 switches, 400 mpps, MSFC3, IOS, CatOS
32 – Cisco 6500 switches, 15 mpps, MSFC2A, IOS, CatOS
V – Cisco 4500 switches, 72 mpps, Integrated Routing, IOS
IV – Cisco 4500 switches, 48 mpps, Integrated Routing, IOS
Switching Module Features
The Switching Module features include – supported switch chassis, interface speed, number of ports, media, cabling, connectors, throughput (mpps), supervisor engines supported, protocol features, power over ethernet (Cisco prestandard or 802.3af).
- Media: Copper, Fiber
- Cabling: UTP Cat 5, CAT 5e, CAT 6, STP, MMF, SMF
- Connectors: RJ45, RJ21, SC, LC
- Transceivers: GBIC, SFP
Power Supply Features
The Power Supply features include – supported chassis, wattage ratings, failover, input/output amps, power cord type, IOS, CatOS.
IOS/CatOS Software
Cisco network switches can be deployed with IOS, IOS and CatOS or exclusive CatOS software. Design features will determine what mode and IOS or CatOS version is selected. The software running on the Route Processor must be IOS while the Engine Switch Processor will run IOS (native mode) or CatOS (hybrid mode). Some Cisco equipment such as the 4507R deploy the Supervisor Engine IV with no MSFC onboard. The Route Processor is integrated with the engine. With that design, the Engine IV doesn’t support CatOS.
Native IOS – deployed at the network edge where most routing occurs and some switching is needed
Hybrid – deployed at the network core where there is both routing and high speed switching
CatOS – deployed at the network access layer where there is switching and no routing
Switch Selection Process:
The following describes the 5 components of any network switch selection process:
1. Consider the network assessment and design features specified
2. Select switches that include all the design features
3. Select switches with proper scalability
4. Balance cost and equipment features while meeting budget guidelines
5. Select IOS and/or CatOS software version
The Network Assessment and design specifications should be considered before selecting any network switches. The network assessment examines the design, configuration and equipment that is implemented at the office where the selected devices will be deployed. The design specifications will determine performance, availability and scalability features needed. Selecting the IOS and/or CatOS version occur after deciding on the feature set. Companies will specify a budget and that is a key consideration with any equipment selection. It isn’t cost effective to select a Cisco 6509 switch for an office with 50 employees. It is important that you select equipment that meet the design specifications, has the scalability features needed while meeting budget guidelines.
Some typical switch features to consider:
1) Are there enough Chassis slots?
2) What Supervisor Engines are supported?
3) Does the Engine support failover?
4) Is Multi Layer Switching available?
5) What Switching Modules are available?
6) What Uplinks are available?
7) What Power Supply wattage is available?
How many Rack Units are needed?
Switch Selection Example:
The Network Assessment discovered the following at the company office.
