Simple IP Phone implementation

[katerina.dardoufa]

Hello all,

I am not all that familiar with VoIP and I have a few questions.

We need to connect a couple of IP phones in our environment. The IP phones need to be isolated and no PCs will be connected to their switch port.

PoE switches will be used to accomodate these IP Phones.

My questions are:

• since data traffic won't be traversing the swithes does QoS need to be implemented (auto qos voip trust - interface command)?

I have read that if QoS is not enabled globally on a switch all  packets/frames are passed through unaltered, meaning that their CoS or  DSCP values are not changed. So if the CoS value of the voice frame is 5, that won't be changed to the default value of 0. Correct?

• I have read that static mac port security cannot be used with the voice vlan. Is that true in practice? If I want to implement port security on the port connected to the IP Phone, what kind of security can be used? (only maximum macs?)

Thank you in advance,

Katerina

[ronpatel]

HI,

1) If you have enough Bandwidth for voice call, you do not need the QOS. But I would say what is harm in enabling quto QOS.

2) You can use  Maximum MAC Addresses for Voice and Data VLANs

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/31sg/configuration/guide/port_sec.html

Regards

Ronak Patel

Rate helpful posts by clicking stars below the answer.

[katerina.dardoufa]

Ronak,

thanks for the link. I had not seen the port-security voice vlan command before, so that serves my needs.

As for auto qos. True... no harm in configuring it anyway...!

[paolo bevilacqua]

You don't really need QoS on switches, not even if there is data traffic. Some people witll tell you otherwise, but that is my expereince of 10 years, and hundreds of installations.

You can configure any port secuirty you want.

[Gordon Ross]

Paolo Bevilacqua wrote:
You don't really need QoS on switches, not even if there is data traffic. Some people witll tell you otherwise, but that is my expereince of 10 years, and hundreds of installations.

You can get away without QoS on the ports which the phones plug into. However, I really would put QoS on uplink/trunk ports. (Unless you have more bandwidth than you can shake a stick at)

GTG

[paolo bevilacqua]

You can get away without QoS on the ports which the phones plug into. However, I really would put QoS on uplink/trunk ports. (Unless you have more bandwidth than you can shake a stick at)

Maybe my customers are light users, but I never see congestions or drops on any trunk (N x Gb ).

[katerina.dardoufa]

I think I will enable auto qos anyway... just to be on the safe side.

Best regards,

Katerina