Just to be sure how Voice Over Ip Works??!!

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Aug 3rd, 2010
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Hello:



I was just having the doubt of the Voice over ip configuration. Not any switch that moves Vlan's, can move the traffic of voice right?

This switches need to have the hardware and firmware that has the capacity of moving this kind of traffic.



Thank You

Gravis

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Jayakrishna Mada Tue, 08/03/2010 - 13:27
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Hi Gravis,


Voice traffic is a UDP. So any switch can forward this traffic. The only differece that switches have when it comes to voice-traffic into picture is when you to prioritize the voice traffic on them.


QoS is platform dependent, so based on the switch or lincard you are using it might or might not support priority queueing.


Hope this helps.


Jayakrishna

gravis0516 Tue, 08/03/2010 - 15:59
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Hello:



Thank you for the fast reply. So in order for VoiP to move over any switch, the switch must have the capability of QoS Service and

the capability of creating Vlan's??!! Im asking this because, im moving a VoiP network to a new building. The thing is that this building already has

a layer 2 infraestructure and the one i'm moving is layer 2 switches that traffic IP and Voice; using a layer 3 master switch and this infraestructure has

a PBX server too. So the problem will be is that this building will have two PBX's and of course the administration won't like to call a neighbor in another cubicule by calling a whole number to get the extension. But at the same time they want two domains on the same building, kind of weird, but orders are orders. So the whole point is to use the existing switches to at least use them for voice traffic, but the exisiting switches are old. Soooo a little help will be nice hehehehe.



Thank You

Gravis0516

Jayakrishna Mada Tue, 08/03/2010 - 18:50
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Hi Gravis,


If I understand correctly you are trying to move the voip traffic from one building (infrastructure) to the other, correct me if I am wrong.


If that is correct all you need is to extend the l2 network (create voice vlan on all the switches in the path ) from one building to another building and still use the L3 switch to routing purpose. What are the switches that you are going to use.



For example if your current voice vlan 2.



phone----old buliding switch----------new building switch----new phone.


Also you need is to establish connectivity on vlan between the two switches. Basically configure a trunk link between two switches and create vlan 2 on the new building switch.


JayaKrishna

gravis0516 Tue, 08/03/2010 - 20:05
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Hi:



Ok, the switches that are moving from the old building are Enterasys, i dont know the model, but they run all that i need, because they are running it right now. The switches in the new building are nortel baystack 350-24T, pretty old switch. I did enter to the console line of this old switch and they can make Vlans, but i dont see anything about Qos in the firmware. Another thing i forgot to write was, that the vlan that we use for voice is the 10, so im guessing that this vlan i have to open it in the switches of the old building, right? The this is that the new building doesn't have a PBX voice over ip, just plane telephones with extension, no ip involved. So the switches just move comm to the computers and servers, so that when all the problem begins. As i mentioned earlier, the switches that the new building are using are pretty old and i dont know if they can be used for Voip. I appreciate the help JayaKrishna.



Thank You

gravis0516

Jayakrishna Mada Tue, 08/03/2010 - 20:14
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Gravis,


I haven't worked with nortel baystack 350-24T so I am not sure if you will be able to achive what you are trying to configure on those switches.


Yes if you can somehow make that vlan 10 is open between all these switches I think that should do the trick for you.


Jayakrishna

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