We have a customer who is using a VoIP box (SPA-2000 from www.sipura.com) and just switched from cable (Comcast) to us. The performance of VoIP calls is unsatisfactory as sometimes there are gaps (3-4 seconds) in the calls. The SM runs 99-100% on link tests with about 3.2mb down and 1.8mb up. Various speed tests run about 2.8mb down and 1.5mb up. If the VoIP box is plugged back into the cable service it is good, but into the SM there are times when the gaps in voice occur. At those times I have checked and I still have several mb of unused capacity to the internet. Also if I plug the Voip box into the CMM at the AP site, the calls are good. I do not have any Advantage hardware, so the APs/SMs are software scheduled. Also I do not have any high priority bandwidth set. Basically setting are default, other than the up/down percentage, which is set to 50%. The VoIP box (SPA-2000) does set the TOS bit to 5. I’m not prepared to set high priority bandwidth since it has to be set on every AP at the site, and for only one customer, I don’t know that I want to do that. Also I don’t know if the cable companies are allocating high priority bandwidth and using the TOS bit to improve VoIP. I assume they are only offering “best effort” service to all traffic.
Could I get responses to determine who has Voip working without high priority settings and who has it working with high priority?
We have several VOIP clients on our network (ones that we know about), some are on 900MHz (Advantage) and some are on LOS non-Advantage links. These all happen to be Vonage customers.
The devices appear to perform better when placed behind a local router (e.g. Linksys WRT54G) than when directly connected to the SM via a switch (e.g. Linksys EZXS55W)… no difference in call quality, but a problem with losing dial tone and requiring a reboot of VOIP box.
Setting the priority channel on the 900 MHz SM does improve overall VOIP performance.
Did this issue ever get resolved I have the same problem with thr spa1001 TEKNIX do you have anything to add? In our case the gapps in transmission are only on the outbound traffic from the spa unit?
Have you QOS Enabled, or have you got any Layer 2 Or Three switches Putting traffic in Priority order. Because if people on your network are downloading useing Peer to Peer Applications or Downloading large files without Qos enabled on your network this will be the effect using VOip.
QOS = Quality Of Service
We are going to launch our VOIP services nationally next week. We have done alot of testing with Canopy and are using Sipura ata’s as well. From my testing without the high priority channel enabled you get choppy transmissions on the uplink side of the conversation. We did not experiance this problem threw a bh. Just by enabling the high priority channel the problem was still their. The Sipura 's default settings do not have bit 3 enabled. With bit 3 disabled the sm does not know to send those data packets up the high priority channel. So yes you need high priority enabled and you need bit 3 enabled in the ata as well. Voice sounds good you do get a slight breakup if you are downloading a big file at the same time. All testing was done on both Advantage and non Advantage AS’s and SM’s in the 5.7 and 900 bands.
Do you happen to know where this bit 3 setting is located in the sipura, I have been playing with a sipura ata and cant seem to find it.
attitude0330 wrote: We are going to launch our VOIP services nationally next week. We have done alot of testing with Canopy and are using Sipura ata's as well. From my testing without the high priority channel enabled you get choppy transmissions on the uplink side of the conversation. We did not experiance this problem threw a bh. Just by enabling the high priority channel the problem was still their. The Sipura 's default settings do not have bit 3 enabled. With bit 3 disabled the sm does not know to send those data packets up the high priority channel. So yes you need high priority enabled and you need bit 3 enabled in the ata as well. Voice sounds good you do get a slight breakup if you are downloading a big file at the same time. All testing was done on both Advantage and non Advantage AS's and SM's in the 5.7 and 900 bands.
But anyway, with limited sustained information rate for ex. to 128 kbit/s voice quality is strongly affected by simultaneous transmission of data.
P.S. We are using non-advantage Canopy
Yes log into the ata
click
admin login
advanced
line 1 tab
under network settings you will see sip tos and rtp tos. these values are in hex form. you have to convert them to binary make your change and then convert it back to hex. But to save you the trouble change sip tos to 0x38 and rtp tos to 0x78. give it a try hope it works for you.