Phones and PCs all together on one segment
Submitted by datakey on Mon, 05/19/2008 - 7:05am.
I have a TB Pro install this week but have yet to determine exactly how I'm going to setup the LAN(s).
It's a small company: 7 phones, 5 SIP trunks, no PSTN gateway
They want to dump their existing DSL and throw everything onto a new (frame) T1.
I already purchased and have received an appliance running TBPro SE and a SIP firewall from Ingate (1190 I believe). The phones are SP942 with a 2-port switch and POE.
All of the systems I've done in the past had the phones on a separate physical network but they did not want to run another set of cables.
I'm considering just using the TBs DHCP server to serve addresses to a single LAN segment with both the phones and PCs all together. There's only one router/firewall anyway and only one internet connection, so what is the advantage of a separate (even virtual) segment for the phones?
Has anyone used the TB this way? Any problems? Any suggestions?
TIA,
Dan
I dont use pro - but all my
Mon, 05/19/2008 - 7:13am
I dont use pro - but all my CE installs have everything together and at 100mbit - I never have any issues. These offices are mostly people using a file server - and any web browsing is on 1.5 or 3.0mbit T1s - so the lan traffic is minimal.
If I can - I have isolated the PBX and phones to their own switch - but many of them have the PCs piggybacking off the phones anyway.
What type of switch do you have.
Mon, 05/19/2008 - 8:56am
You did not mention in your OP what type of Ethernet switch you have.
I would suggest using a Linksys POE switch. This switch is managed and will allow you to power all the phones off the UPS.
In addition a managed switch will allow you to use VLAN's the switch in the phone will separate the voice and the LAN traffic and assign the correct priority. This is how the phones are designed. Placing them all on the same network is not proper practice. If one of your PC's has a problem and starts hammering the network do you want your phones to go down?
The Linksys switch has a web interface and it takes about 10 minutes to setup the VLANS.
To make it simple put two interfaces in the trixbox. One for the Web GUI/Management and for downloading the updates the other for the phones.
Run DHCP on the trixbox only for the phones.
Make sure your router has the ability to set priority for voice (RTP) traffic.
Scott
--
Scott
aka "Skyking"
DHCP to two different VLANs. How to separate devices?
Mon, 05/19/2008 - 9:26am
I am using a POE switch but not a Linksys. Its a Planet EPOEMS12.
How does the manages switch differentiate between the phone and a PC? i.e. How does it know which address segment a device belongs to? Is it by MAC address/MAC prefix?
If not using a Managed switch and instead using DHCP (in TB or otherwise)... same question. I know entries in the dhcpd.conf file allow doleing out addresses by MAC address but I wanted to avoid the hassle if there was another way.
TIA,
Dan
Datakey, Inc.
Listen, Solve, Implement
VLAN Tagging
Wed, 05/21/2008 - 11:12am
Dan,
Most switches allow you to apply VLAN (802.1q or ISL) tagging once you have your VLAN's set up correctly. You can assign various ports on the switch to "tag" the frames with their proper VLAN id, which ensures that all traffic from either VLAN is correctly directed across a trunk to it's destination. The switch will worry about keeping track of which frames are tagged based on their MAC addresses, so you won't have to make any changes in dhcpd.conf for this to work correctly.
In the case that you're not using a managed switch, you would have to use two separate switches and subnets/networks in order to keep the traffic separated. If you wanted to use your trixbox as a dhcp server you will need to route between the subnets and then modify dhcpd.conf so that it applies IP's based on MAC reservations....it's a bit more work, so I'd recommend using the managed switch approach.
Joe
Member Since:
2008-01-30