3560G PoE query

[nilesh_sawant]

Hi,

I am observing the problem with 48 port- 3560G in LAN infrastructure. We have alcatel IP phone which are connected to 3560G switches. Sometimes these IP phone are not getting power up or if i disconnect & connect the IP phone again then it's on powering up. Also sometimes near @ half of the IP phones connected from the switch are working & half not.

After restarting the switch, IP phone gets power up.

What could be the issue ?

Regards,
Nilesh

[nilesh_sawant]

Hi,

I am observing the problem with 48 port- 3560G in LAN infrastructure. We have alcatel IP phone which are connected to 3560G switches. Sometimes these IP phone are not getting power up or if i disconnect & connect the IP phone again then it's not powering up. Also sometimes near @ half of the IP phones connected from the switch are working & half not.

After restarting the switch, IP phone gets power up.

What could be the issue ?

Regards,
Nilesh

[Leo Laohoo]

How many PoE ports are active?

When you get a 48-port PoE port (this rule-of-thumb does not include 3560E/3750E), do NOT expect PoE to all 48-ports.  Realistically you will only get PoE to the first 24-port "first-come-first-serve-until-exausted".

It doesn't matter if the PoE allocated is 7.5w or 15.4w.

Hope this helps.

If this answers your question, please don't be reluctant to rate my post appropriately.

[nilesh_sawant]

Hi,

I have total 37 alcatel IP phone connected to 3560G. All are working fine but sometimes few of them gets power-off while others are still working.

There is no definite no.s of IP phone working or not working.

Reagrds,

Nilesh

[vvasisth]

besides that do you get any error message respective to the [ports which stops supplying poe to phones ?

[vvasisth]

in your case there could be a couple of reasons for the same :-

1 -- on 3560 only half ports can provide POE at one time

2 -- i am not sure how much power is required by alcatel ph ut you can statically assign power to ports with the amount of power required by phones.

3 -- Check the output of show [power inline and get the output

[Leo Laohoo]

The Catalyst 3560G-48 PoE configurations can deliver the necessary power to support 24 ports at 15.4W, 48 ports at 7.7W, or any combination in between.

Use the command "sh power inline" to find out if you have run out of power allowance for the phones.

Reiterating my initial post, only the 48-port switch of the 3560E and the 3750E that can delivery full 15.4w of PoE power to all ports.  This category of switch also support enhanced PoE (up to 20.0w).

Another way of testing is to move the phones that doesn't seem to power to another PoE port.

[nilesh_sawant]

Hi,

No error message when i discconnect from switch & connect it

Alcatel phone requires 36-52vdc, 0.1-0.2a.

As seen from the sh power inline o/p few phones are detected as class-0 so consuming 15.4w.
Now I have configured "power inline consumption 7000" on the ports which are detected as class-0
Hope this will solve the issue.

Sales#sh power inline | i on

Gi0/2     auto   on         7.0     Ieee PD             2     15.4
Gi0/4     auto   on         7.0     Ieee PD             2     15.4
Gi0/6     auto   on         7.0     Ieee PD             2     15.4
Gi0/8     auto   on         7.0     Ieee PD             2     15.4
Gi0/10    auto   on         7.0     Ieee PD             2     15.4
Gi0/11    auto   on         7.0     Ieee PD             2     15.4
Gi0/12    auto   on         7.0     Ieee PD             2     15.4
Gi0/14    auto   on         15.4    Ieee PD             0     15.4
Gi0/15    auto   on         15.4    Ieee PD             0     15.4
Gi0/17    auto   on         7.0     Ieee PD             2     15.4
Gi0/20    auto   on         7.0     Ieee PD             2     15.4
Gi0/23    auto   on         7.0     Ieee PD             2     15.4
Gi0/27    auto   on         7.0     Ieee PD             2     15.4
Gi0/30    auto   on         7.0     Ieee PD             2     15.4
Gi0/31    auto   on         7.0     Ieee PD             2     15.4
Gi0/34    auto   on         15.4    Ieee PD             0     15.4
Gi0/35    auto   on         7.0     Ieee PD             2     15.4
Gi0/36    auto   on         7.0     Ieee PD             2     15.4
Gi0/37    auto   on         15.4    Ieee PD             0     15.4
Gi0/38    auto   on         7.0     Ieee PD             2     15.4
Gi0/39    auto   on         7.0     Ieee PD             2     15.4
Gi0/42    auto   on         7.0     Ieee PD             2     15.4
Gi0/43    auto   on         7.0     Ieee PD             2     15.4
Gi0/44    auto   on         15.4    Ieee PD             0     15.4
Gi0/46    auto   on         7.0     Ieee PD             2     15.4
Gi0/48    auto   on         7.0     Ieee PD             2     15.4

[Leo Laohoo]

Try the following:

1.  Use power injector
2.  Swap out the ports to the ones that are working
3.  Get another PoE switch