campus network and wan

[sarahr202]

Hi everybody.

My book says " A campus network is an enterprise network consisting of many lans in one or more buildings, all connected and usualy in the same geographic area.Campus network commonly consists of ethernet.802.11 wireless lan,high speeds fastethernet etc."

However,  I was watching CBT CCNP switch video and learned  high speed wan can also conects different blocks within campus.

Let say we have a fictious company " ABC inc" with offices ( buildings)  as show below:

Building1 in California (CA)

Buiding2 in  Newyork(NY)

Building 3 in Indiana(IN)

Building 4 in Hawaii

Building 5 in Washington.

Just focus on two offices which are connected as shown below:

building 1(CA)( access layer)------Distribution sw--wan------core--wan---distribution sw---building 2 NY( access layer)).

Can the above network still be considered as campus network considering the fact a wan is used between distribution layer and core layer?

thanks and have a great week.

[Amit Singh · Accepted solution]

Hi Sarah,

The above topology will not be considered as Campus network as you have three different geographic areas in 3 diff cities connected together with WAN. I would consider a Typical WAN connectivity if you have an MPLS service provider connecting these 3 locations.

If you have a large campus with different buildings within the same city, typically you would connect those to a high-speed core which could be your WAN termination router like Cat6500/7600 and route the traffic between the buildings. This would be an example of using the high-speed WAN/Core to connect different campus blocks.

Hope this helps.

-amit singh

[sarahr202]

Thanks Amit.

The reason the network in question is not considered as campus network because  it spans different geographical regions not because they are connected by wan.

My question is what wan technology commonly used to  connect a distribution layer to core layer? for example

Three offices buildings are located  in Newyork city as shown below:

Building 1( access layer) ---distribution layer--wan--coreswitch( 6500 cat)-Wan---distribution layer--building2 ( access layer)

What wan technology is used usually  between distribution layer and core 6500 cat switch? in other words, what Wan modules are available for cat 6500 switch ?

thanks and have a great week.

[Amit Singh · Accepted solution]

Hi Sarah,

Typically within a campus environment you would use an Gigabit ethernet fiber connectivity. In the above example, if your Cat6500 is acting as a WAN router/switch, your ISP WAN can either terminate on Ethernet or T1/T3 WAN modules. Your building 1 and building 2 will connect using Fiber connecvitity directly to Cat6500 which will route/switch the traffic between the buildings.

In your example, I would use L3 connectivity from buildings to connect back to Core/WAN switch. This way, your vlans will be local to each building/site and you would use L3 routing for backbone communication without extending your STP to the core/WAN layer.

Hope this helps.

Cheers,

-amit singh

[sarahr202]

Thanks Amit.

I should have been more specific in my question.    In my example, vlan does end at distribution switch because it is multilayer switch. I

I am just curious if you have ever seen where a multilayer distribution switch is connected to core multilayer switch via ATM ot T1 orT3  in campus network?

building(access)-------trunk---multilayer distribution switch------layer3 connectivity-------Core multilayer sw

thanks and have a great week

[Amit Singh · Accepted solution]

Hi Sarah,

Yes, I have seen that long back during my early networking days. I used to work for a Contact center company and they have had this kind of set up with E3 in asiapac. They had 2 buildings which were around 20 miles apart. They could not get a direct fiber stretch between the buildings as they had different SP at both ends and also the SP could not dig a fiber cable between the buildings due to government restrictions. They had E3 connectivity between the sites using L3 peering on EIGRP. One ISP was for their WAN internet connectivity and another one for E3 connectivity between the sites using Cat6500's as the distribution and core switches. Building 1 with internet WAN connectivity was the gateway for building 2 and the whole traffic was routed to building 1 for internet exit.

Cheers,

-amit singh

[Joseph W. Doherty · Accepted solution]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Can the above network still be considered as campus network considering the fact a wan is used between distribution layer and core layer?

Not really because of a key difference between campus networks and WANs - physical distance.  You can obtain high bandwidth WAN links, like LAN links (although usually much, much more expensive) but you can not obtain LAN, or campus network like, latencies on WANs.

[sarahr202]

thanks JosephDoherty

then what is physical distance limitation for a campus network to be considered as a campus network? for example if we have to connect multilayer distribution sw to core switch how far they could be at most to be in a campus network?

How about if we connect multilayer dis sw to core layer via metro ethernet , will  it be considered a campus network ?

thanks

[Amit Singh · Accepted solution]

Hi Sarah,

I think it would be safe to say that if you have MAN ( Metroplitan area network) campus all connected via dark fiber or metro ethernet with pure L2 connection which can easily pass L2 traffic without much of the challenges like latency and delays, it could be considered as a Campus network. Typically, a campus network is the one which can run direct point-point fiber cables between the sites without needing a 3rd party invlovement. Say, your Bldng 1 and Bldng are connected via a point to point fiber connection, this could be considered a campus extension. If you want to connect Bldng 3 to Bldng one via Ethernet over MPLS using a SP, it cannot be considered as a true Campus extension as you have another SP network invloved which would impose some extra delays,hops and latency as your L2 traffic would move across SP network to reach other side. This will have different characterstics than the pure L2/L3 point-point Fiber connection.

My example can be a lillte unclear, Sorry in advance is its so.

Hope this helps.

Cheers,

-amit singh

[Joseph W. Doherty · Accepted solution]

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

then what is physical distance limitation for a campus network to be considered as a campus network? for example if we have to connect multilayer distribution sw to core switch how far they could be at most to be in a campus network?
How about if we connect multilayer dis sw to core layer via metro ethernet , will  it be considered a campus network ?

For physical distance, I would suggest about a mile or couple of KM, or so.  Think typical college/university campus or business campus.

As to using metro Ethernet, again it's really a question of bandwidth and delay.  I've worked with public provider networks that provided inter-building connectivity where the buildings are directly across a (public) street or just down the block.  These performed the same as a network between buildings on a private campus.

I've also worked with public MANs interconnecting across a (large) city, and for those, they no longer have typical campus like latencies.