WLAN as an alternative to leased line. Stewart Sharpe.
Cisco Systems. 3Com. BreezeCOM. Culubris. Lucent. Enterasys. SpectraLink. Intersil. Vendor neutral supplier. Mobius Technologies Ltd. can supply solutions from a huge range of vendors on an impartial basis. These include: -
Basis for choice of solution. • Reliability. • Application suitability including security. • Expandability. • Upgradeability and investment protection. • Customer support. • Cost effectiveness.
Solutions to be highlighted. Cisco Systems – Aironet. 3Com – Airconnect.
2 different applications to be studied. • Huge number of scenarios available to us for each solution. • We have chosen straightforward scenarios for demonstration. • Case studies later, will expand up on this basic representation.
2 different applications to be studied. Cisco Systems – Aironet. • Point-to-point/multipoint link between buildings. • Applications with specific or extended coverage requirements. 3Com – Airconnect. • Office environment LAN.
Scenario 1. Multi-building LAN extension.
Scenario 1. 1. Main office building. Centralised location of: - • File servers. • Mail server. • Internet connection.
Scenario 1. 2. Sub-office within the main campus. • Office uses all facilities of main office. • 15 network users.
Scenario 1. 3. Sub-office within main campus. • Office uses all facilities of main office. • 30 network users.
Scenario 1. 4. Sub-office outside main campus. • Office uses all facilities of main office. • 15 network users. • Public road between office and main campus.
Options for extending network. Campus buildings 1, 2 & 3. • Wire between buildings. • Fibre between buildings. • Wireless bridge between buildings.
Characteristics of options.Wire/fibre between buildings 1, 2 & 3. Benefits. • Limitless bandwidth possibilities. • Permanent link with little maintenance. • One off installation costs.
Characteristics of options.Wire/fibre between buildings 1, 2 & 3. Drawbacks. • Typically would be buried in ground. • Huge upheaval to existing features e.g. car parks, footpaths, landscaping etc. • Time consuming and costly installation. • No benefit in relocation.
Options for extending network. Buildings 1 & 4. • Dial-up connection between buildings. • Leased line between buildings. • Wireless bridge between buildings.
Characteristics of options.Dial-up connection. Benefits. • Easy quick installation using existing lines. • Adequate for occasional usage. e.g. Weekly submission or update of files. • Can be used in multiples to increase bandwidth. • No office relocation issues.
Characteristics of options.Dial-up connection. Drawbacks. • Very slow for all but most basic tasks. • Multiple connections increase unit costs. • Inconvenience of repeated reconnection. • High relative costs.
Characteristics of options.Leased line. Benefits. • Permanent link. • Huge bandwidth availability. • Reliable connection.
Characteristics of options.Leased line. Drawbacks. • Not always possible to install. • Expensive installation costs. • High periodic costs for higher bandwidth. • Long lead times for installation. • Relocation requires re-installation.
Characteristics of options.Wireless bridge. Benefits. • Very quick and simple installation. • No periodic charges. • 11Mbps bandwidth. • Permanent link. • Easily relocated.
Characteristics of options.Wireless bridge. Drawbacks. • Requires clear line of sight between points. • Bandwidth diminishes as distance increases. • Site survey necessary as a pre-requisite.
Site survey. Necessary to ensure the following: - • That no unforeseen circumstances render system unsuitable - prior to purchase. • Highlight precisely what will be available. • Accurately specify equipment required for quotation purposes. • A clear picture of physical layout in advance.
Costings.Scenario 1. Suggested. • Point-to-multipoint link between 1 & 2, 1 & 4. • Point-to-point link between 1 & 3.
Costings.Scenario 1. • Allows 11Mbps to be shared between the 1 - 2 link and the 1 - 4 link. • Allows a full, separate 11Mbps link between 1 & 3.
Costings.Scenario 1. Site survey. • 2 people on-site for 2 days. Point-to-multi-point link. • Bridge and omni antenna for building 1, bridge and yagi antenna for each of building 2 & 4. Point-to-point link. • Bridge and yagi antenna for buildings 1 and 4.
Costings.Scenario 1. Installation. • 2 people, 5 days. Additional equipment. • Lightning arrestor per location. • Antenna mounts and connectors.
Costings.Scenario 1. Additional costs (unknown.). • NEMA enclosure per location. • Electrical contractor to provide supplies to enclosures and earth lightning arrestors. • Any masts required to gain line-of-sight.
Summary of benefits. • Bandwidth adequate for most applications. • No periodic costs. • Quick and easy installation. • Short lead times. • Ideal in difficult situations. • Easily relocated with the business. • No license required.