Broadcast Domains & VLANs

[visualspirit]

Hi,

We will soon be installing a CXi II with a company. They are having 30 phones.

We don't want to put all these phones on the same broadcast domain, but although I understand VLANs I have never really experimented.

Their IT guy is not interested in messing about with their network side, but we have to put it on their LAN to allow for internet access and user configuration.

So I guess what I'm asking is what's the best way to go about this and future projects?

Cheers,
Bob.
 

[acejavelin]

30 phones in it's own broadcast domain (VLAN) should be fine, we have individual voice VLANs with hundreds of phones, as long as it is setup correctly there shouldn't be an issue...

How to set this up will vary based on the network configuration and networking equipment being installed, there are numerous ways to do this... via DHCP hand-off, Cisco SmartPort, LDAP, hard coding phones, etc, etc... Each instillation is unique, although there are general guidelines it will vary depending on any number of circumstances, and each tech here will probably tell you a different way to implement this, and they are all probably "correct".

[johnkeri]

That is a bit loaded question.
First of all the design of these deployment:
- Separate network for phones with their own network drops?
- The CXi has a built in switch for 16 ports and there are 30 phones

Otherwise:
You connect to the firewall from the LAN port of the CXi and let the firewall do all the routing and filtering.
What you really have to watch for is the DHCP broadcast. Keep it in the voice network.

[LoopyLou]

Typically you would want to seperate voice and data traffic on a network. Voice packets need priority over data packets when it comes to travelling on the network. To seperate the voice traffic they would need to create a voice VLAN on the network and assign the phones to that voice VLAN either throught DHCP or using CDP or LLDP on the networks switches.