Network Issues With HP ProCurve Switches and IP Telephony

[guygreen]

Hi,

Lately I'm having issues in my network, mostly with the IP Telephony.

Network Topology:

A little network description - The center of the network is the 3COM BB switch.

I have a section called "A4" which consists of 5 access switches (marked red) and they are eventually connecting to the BB switch.

2 of them directly and 3 others one to each other.

I have around 200 IPTel's and PC's which are connected to those access switches.

In order to minimize needed ports, we are connecting the PC's and IPTel's in the following way:

PC -> IPTEL -> Switch

The issues we are having are with the IPTel's:

- Interruptions

- Noises

- Silence

- Call disconnections

- IPTel rebooting itself (the IPTel's are PoE injected from the access switches)

Do you have any idea wigh might be the cause and I should be checking in the network?

Equipment used is:

3COM 5500G - BB

3COM 4210 - Access

HP 2530-48-PoEP

HP 2610-48-PWR

AVAYA 16xx/19xx IPTel's

[Vince-Whirlwind]

First step is to determine your power budget:

 a- how much power does each model phone consume when in use? (They use more if they are running at 1Gb than iif at 100Mb)

 b- how many phones of each type do you have on each switch?

 c- how much PoE power does this add up to for each switch? How much PoE power is used by other devices (eg WAPs) on each switch

 d- how much PoE power can each switch provide?

 e- If d minus c equals a small number or a negative number, than you are in trouble 

Then you have to think about QoS - do you even have QoS configured?

Where you have 4 switches daisy-chained one from the other, check out the uplink ports on each of them to see how congested they get as you get closer to the core switch.

If these uplinks are congested, then you absolutely need QoS to prioritise the voice packets.

[guygreen]

Hi Vince,

Power Budget:

a - in idle state I can calulcate an avarage of 3.5w per phone unit, in maximum consumption it might be 5.7w

b - I don't have the type per port allocation right now, but in total it's about 40 IP Telephone's on each switch (about 200 in total).

c - currently the IP Telephony is idle, without any usage and I see that in average it uses 30% of total power capacity on each switch.

d - the 2530 models provide 382w, the 2610 models provide 406w.

e - currently I can't detect a trouble with PoE

QoS:

We have a seperate VLAN for IP phones which is priorotized as Voice