# Viatalk VOIP and 900
**URL:** https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920
**Category:** PMP
**Created:** [December 17, 2009, 9:05pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920 "2009-12-17T21:05:34Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@johnc17403](https://community.cambiumnetworks.com/u/johnc17403)
#### Post date: [December 17, 2009, 9:05pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/1 "2009-12-17T21:05:34Z")
I have a customer with 900 sm and a Viatalk VOIP phone for her business. The voip cuts in and out while the 900 stay in session. What I see is in Statistics / overloads the numbers rapidly go up when using the VOIP phone. I have QoS enables (for bandwith control) broadcast/multicast is enabled with a data rate of 1 kbps. No one else off that same AP is expericing the same problems. I have other VOIP customers that do not have any issues either (using other service like Vonage). Any ideas?
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### Author:  [@VLAN1](https://community.cambiumnetworks.com/u/VLAN1)
#### Post date: [December 18, 2009, 1:47pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/2 "2009-12-18T13:47:42Z")
In our experiences 900 canopy just is not robust enough to support VOIP with any sort of quality.
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### Author:  [@amd\_phreak](https://community.cambiumnetworks.com/u/amd_phreak)
#### Post date: [December 18, 2009, 2:44pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/3 "2009-12-18T14:44:38Z")
No problems here VLAN1.
I run it at home, and I have zero LOS to the AP (heavy pines and other trees in the way). I know many customers who run it on their 900 links from us that have LOS as well. No problems.
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### Author:  [@johnc17403](https://community.cambiumnetworks.com/u/johnc17403)
#### Post date: [December 18, 2009, 8:39pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/4 "2009-12-18T20:39:42Z")
The thing that troubles me is that at times the customer never has problems. I have got other customers with VOIP and never hear from them. I am wondering if this is related to a compatability issue with Viatalk? One of our techs use Vonage and no issues. Radios are configured same way, just different towers. This is driving me crazy!
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### Author:  [@promelas](https://community.cambiumnetworks.com/u/promelas)
#### Post date: [December 19, 2009, 3:08pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/5 "2009-12-19T15:08:20Z")
Do they have a router? If so, maybe try port forwarding. ViaTalk has 3 ports that need to be opened on the router. Go to [http://www.portforward.com](http://www.portforward.com) --\> select their router --\> select ViaTalk. You will want to give their ViaTalk ATA a static IP (e.g. 192.168.1.200) and setup the port forwarding for that IP on the router.
Also, if you haven’t already, for VoIP, login to the SM, go to Configuration --\> Quality of Service (QoS) --\> enable Hi Priority Channel --\> Save Changes --\> then under Hi Priority Uplink and Downlink CIR fields type --\> 256 --\> Save Changes --\> Reboot.
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### Author:  [@VLAN1](https://community.cambiumnetworks.com/u/VLAN1)
#### Post date: [December 21, 2009, 6:47pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/6 "2009-12-21T18:47:36Z")
> | amd phreak wrote: |
> | --- |
> | No problems here VLAN1.
>
>
> I run it at home, and I have zero LOS to the AP (heavy pines and other trees in the way). I know many customers who run it on their 900 links from us that have LOS as well. No problems. |
How many users are on your AP?and what kinda QOS settings are you using? the only time we see VOIP work somewhat okay on 900 is if the AP has less than 20 subs
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### Author:  [@nucoles](https://community.cambiumnetworks.com/u/nucoles)
#### Post date: [December 21, 2009, 9:32pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/7 "2009-12-21T21:32:07Z")
Enable DiffServe throughout network back to the backbone router. Iff possible turn on hi priority queue for porblem customers upto aroun 80-100 kbps.(if possible) Diffserve should help out with the QoS of VOIP traiffc
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### Author:  [@twinkletoes](https://community.cambiumnetworks.com/u/twinkletoes)
#### Post date: [April 16, 2010, 8:43pm UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/8 "2010-04-16T20:43:36Z")
If the QoS isn’t matching the packets properly, then the canopy’s tiny queues will drop voip packets left and right if they are doing almost anything else. So make sure QoS is setup…
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### Author:  [@Chris\_Bay](https://community.cambiumnetworks.com/u/Chris_Bay)
#### Post date: [April 21, 2010, 12:58am UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/9 "2010-04-21T00:58:11Z")
you also must have atleast 1 control slot configured on the AP or your QoS settings won’t help… we found this out the hardway, now we have 900 MHZ Aps with 50 or so ppl on it, we do get some overload on CoS0 LUIDs but NO loss for the prioity LUID ques.
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### Author:  [@custcomp](https://community.cambiumnetworks.com/u/custcomp)
#### Post date: [April 21, 2010, 3:36am UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/10 "2010-04-21T03:36:25Z")
I show a packet overload count of 1592712 on one of our 900APs, but the discards are 0. Is this something I should be concerned about? I have not looked at that page in the past before reading this thread. We have 79 subs on that radio, with 3 control slots.
Thanks.
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### Author:  [@Chris\_Bay](https://community.cambiumnetworks.com/u/Chris_Bay)
#### Post date: [April 29, 2010, 1:42am UTC](https://community.cambiumnetworks.com/t/viatalk-voip-and-900/35920/11 "2010-04-29T01:42:02Z")
did you check your radio and ethernet discard count? over 1 million discards… yes you should be worried may be a problem or your AP is overloaded.