voice and data vlan

Hi ,

I have a linksys cisco slm248 G switch I tried connecting it to our network and all my ip phones stopped working.

we have a network of two cisco 3560 G switches,
Two IP Based VLANS One for Data and one for voice.

whenever i try to connect this linksys cisco smartswitch slm248G switch in my network all my IP Phones stopped working.

what could be the cause.

Help in this regard is appreciated.

Please give us some more info on how you have configured your VLANs on the 3560 G switches then a more detailed answer can be given.
The linksys switch you are trying to connect might have been previously pre-configured and the configuration still exits in its non-volatile RAM (NVRAM). It might be that the switch has ports configured as trunk ports which means when placed in a network it can set itself as the root bridge and alter the VLAN settings of the other switches.
My advice would be to erase the Start-up configuration of the switch and reboot it, then reconfigure it as a virtual trunking protocol (VTP) client and connect to the network.
I stand to be corrected though.

We really need more information regarding your issue. like your Design structure, how your CME, switches and Ephones are setup. And how are trying to plug this switch into your VoIP network and why you need it.

I would try with the basic troubleshooting steps:

1. see your IP Phones screens what are they saying when they bootup? do they say "Auto Registering" do they get their extensions but they are not able to make any calls?

2. go to your CME Router and see if any ephones are trying to register:

CME#show ephone
or
CME#show ephone attempted-registrations

check if your IP Phones are reaching your CME Router and they are trying to register!

3. Do you have IP helper-address setup on your CME router to point to your DHCP Router? maybe they are unable to get IP Address and this will prevent them from getting the IP address of your TFTP server.

4. I would go to my DHCP Router and add the "Option 150 IP address" in my DATA network. yes, in this way even your IP Phones are somehow by mess configuration falling into your DATA network and getting IPs from your DATA network DHCP POOL they would have the TFTP server IP and they would eventually be able to contact your TFTP Server and get the cnf file ,the required configration file for registering with your CME router. by this way your IP phones will be able to function even if they falled into the wrong DHCP subnet.

Are you plugging your IP Phones to the Linksys SmartSwitch? maybe it is missing up your VTP Domain! or maybe it is unable to do 802.1Q Trunking with your Cisco Catalyst 3560G

Anyway these are all simple suggestions to try out. and we might not be able to help you more if you didn't provide us with a detailed information an even some configuration structure.