Life in the Data Center

Road to Highly Available Asterisk Server – Step 2 – Router. Do you need one?

So you have a basic switched network.  The next question is do you need a router?  Well if you want to have separate vLan’s, then yes, you do.  If you want a single “flat” network and keep it simple, then no, you do not.  So what are the pros/cons of each one?  Well in a nutshell.

Flat network.

• Pro-Simpler
• Pro-Less Complex
• Pro-Less expensive – No routers
• Pro-One network domain – Everyone hears everyone
• Con-Susceptible to broadcast storms or single nic errors which can cause issues for the entire network.
• Con-One network domain – Everyone hears everyone.  This can also be a disadvantage.

VLAN Network

• Pro-Versatile – Vlan’s can be separated by access lists for improved security
• Pro-Distance – Vlans’s overcome 100m distance limitations common in larger installations.
• Pro-Creates broadcast domains between Vlans and that helps with broadcast and nic issues.
• Con-Expensive.  You need routers and more devices to create a sound network.
• Con-Complex.  You need more skills and experience.

Which one is right for me?  Depends?  If you need to separate traffic for any reason, then yes, you may need multiple vlans.  Separating traffic is handy for various reason.  You can separate telephone and video traffic from regular PC traffic.  Put them on separate vlans.  This way you may have a better opportunity to outlast a pc/desktop issue that is causing performance traffic on the pc/desktop vlan.  This way you are saying you want your phones to work no matter what.  Now there are other items you must do to ensure that actually occurs, but one thing is certain.  If they are all on a single network (no vlans) and that network is hosed.  Then everything is hosed.  Separating traffic to vlans will many times help mitigate these types of outages.

So for me.  I will try and get my phones on a separate vlan and see how it goes.  Its more complex, but I want to give it a try.