How to Build a CAN Last Update 2007.05.27 1.0.0 Copyright 2000-2007 Kenneth M. Chipps PhD 1

How to Build a CAN

Last Update 2007.05.27

1.0.0

Copyright 2000-2007 Kenneth M. Chipps PhD www.chipps.com

1

Objectives of This Section

• Learn– What a CAN looks like in general– This does not include every single detail, just

the general approach to take to build such a thing

– The rest of the details are in other presentations

Copyright 2000-2007 Kenneth M. Chipps PhD www.chipps.com 2

What is a CAN

• A CAN – Campus Area Network connects multiple networks with easy walking distance of each other

• Let’s look at three examples of what would constitute a CAN

• Then we’ll look at the specific equipment required to setup a CAN


What Does a CAN Look Like

• The simplest CAN just connects two buildings horizontally

• Think of this view as being from above


Building A Building B

Cable


• In this example the most common way to connect the two buildings is to use fiber optic cable run underground from an entry point in each building

• Inside each building the fiber is run from the exterior wall through the air space above the ceiling to the LAN room just like any other cabling



• In the LAN room the fiber is connected into the LAN through a switch port


What Equipment is Required

• For this simple two location CAN let’s look at an equipment list from a Siecor catalog

• Siecor is a company that makes the parts required to create such a thing, as do many other companies

• Siecor is now part of Corning Cable Systems

• This is just an example of one way to do this


What Equipment is RequiredLocation Quantit

yPart Number Description

Building A 1 WCH-04P Wall Mount Cabinet

1 CCH-CP06-59 SMF Patch Panel

2 CCH-CP06-91 MMF Patch Panel

6 95-000-41 SMF SC Connectors

12 95-200-40 MMF SC Connectors




Underground How ever many meters of fiber as are required

018XW4-AI420A20 Altos Loose Tube Fiber Optic Cable with 12 MMF and 6 SMF




Building B 1 WCH-04P Wall Mount Cabinet

1 CCH-CP06-59 SMF Patch Panel

2 CCH-CP06-91 MMF Patch Panel

6 95-000-41 SMF SC Connectors

12 95-200-40 MMF SC Connectors



• Let’s look at some pictures of these parts as provided by the Corning web site



• Wall Mount Cabinet - WCH-04P



• SMF Patch Panel which mounts in the cabinet on the right side where the ovals are shown - CCH-CP06-59



• MMF Patch Panel which mounts in the cabinet on the right side where the ovals are shown – CCH-CP06-91



• SMF SC Connector which mounts to the back side of the patch panel – 95-200-41



• MMF SC Connector which mounts to the back side of the patch panel – 95-000-40



• Altos Loose Tube Fiber Optic Cable with 12 MMF and 6 SMF - 018XW4-AI420A20



• The parts shown here all mount to a wall• The same thing can be done using a relay

rack, which is attached to the floor, and patch panels of the same sort that mount to the relay rack, instead of to a cabinet as shown above

• The parts that connect to this hardware just discussed, like switches are discussed after the next example of a somewhat more complex CAN



• A more complex CAN would still connect horizontally but connect more than just two buildings


Building C

Building B

Building D

Building A


• In this example four buildings are connected using fiber optic cable run underground from an entry point in each building to a single building

• A CAN is wired just like a LAN, in other words in a star pattern



• Inside each building the fiber is run from the exterior wall through the air space above the ceiling to the LAN room just like any other cabling

• In the LAN room the fiber is connected into the LAN through a switch port



• As discussed above a CAN usually connects physically separate buildings by installing cable horizontally

• However if you are connecting floors in a single building vertically, when does the distance make this a vertical CAN instead of a backbone

• Who knows, doesn’t really matter



• Just keep in mind that the techniques used to make horizontal connections can be run vertically as well





• The first thing used is a cable to connect the sites

• It does not matter whether it is one site or several sites

• Once the cable is in place the next step is to connect it to the equipment at each site

• What kind of equipment depends on what the rest of the network will look like



• Some examples are mentioned next• Do not rely on the equipment mentioned

specifically, since they are just for illustration purposes

• The exact manufacturer and model is not as important as the concepts discussed



• In general for a simple CAN an Ethernet Layer 2 switch is used

• An example of this type of switch suitable for an average size LAN in each building who have users who need to share with the other building or just talk to users in the other building would be a Cisco Catalyst 2900



• The only other question is what type of fiber to use and therefore what type of fiber port is required in the switch

• This question is answered by looking at the distance between locations and the capacity or speed required for the connection

• Gigabit – 1000 Mbps – Ethernet is the usual choice



• 1000BaseSX – Short Wave Length– Uses a short wave length laser - 850 nm -

usually over multimode fiber optic cable– Using 62.5 um multimode the distance limit is

220 to 275 m– Using 50 um multimode the distance is 500 to

550 m



• 1000BaseLX – Long Wave Length– Uses a long wavelength laser - 1,300 nm -

over multimode or single mode fiber optic cable

– Over 62.5 um multimode fiber the distance is 550 m

– Over 50 um multimode fiber the distance is 500 m



• Of course this is a flat design and does not scale well

• Since the use of layer 2 switches puts all of the devices in the same broadcast domain and a single IP subnet

• Another advantage to a layer 2 switch is it requires no configuration, such as a router does



• If the campus or traffic over the links grows this can be changed to a hierarchical design by just changing the model of the switch to one that operates at layer 3 or putting a router on each side of the fiber

• To move up the switch would need to be replaced with a switch that can operate at layer 3 and has more fiber ports



• For the four building CAN shown above a layer 3 device is called for

• For example a Cisco 3508 XL has 8 fiber ports, which would work for our example site



• In this particular switch the front has nothing but slots

• Modules are inserted into these slots• In this case we would need 4 GBIC –

Gigabit Interface ModulesCopyright 2000-2007 Kenneth M. Chipps PhD www.chipps.com 34


• 3 of the GBIC modules would connect to the fiber coming in from the other three buildings



• The fourth GBIC module would connect to a layer 2 switch that would contain the copper ports used to connect the LAN in each building to the CAN for all of the buildings

• Another model Cisco Catalyst 2900 for example



• The servers and workstations are then plugged into the copper RJ-45 ports shown along the bottom of the switch


Review

• What is a CAN


Documents

How to Build a CAN Last Update 2007.05.27 1.0.0 Copyright 2000-2007 Kenneth M. Chipps PhD 1