I have a site where there are SPA525g2 with latest firmware 7.4.9a and IP Communicator , the IP communicator with anyconnect works perfect voice quality and no noise ,but SPA525g2 on the same sites has voice breaking problem plus there is noise like (SHSHSHSH) why Cisco makes perfect software but bad hardware , I tried all codec no use , I opned ticket with Cisco till now no use .
anyone has this issue before please tell me how you slove it .
I have heard a customer experiencing a similar audio quality issue with the SPA303 phones, but their phones were not connected to a UC300 or UC500. This audio quality issue only appears to occur with audio coming into the phone and out of the handset, and does not appear to occur with audio from the microphone and coming out of the phone. They are using firmware version 7.4.9a. They do not experience this issue with every single call. Is there a firmware update that will improve the audio quality with the SPA30x and SPA50x phones?
Is the issue on the "A" End or the "B" End? ("A" Being your end, "B" being the far end)
I find the audio quality improves when using digital lines such as ISDN, and a vast improvement when using ISDN/PRI and on sites where they are using analogue lines the audio quality is below ordinary, at one site Cisco even replaced all 15 phones with the NBD replacement and still the problem persisted.
I have been quite critical of the voice quality on the SPA phones for a while now, and am still critical of them, it seems price in this regards does indeed have something to do with it, I would rather sell the 6900 series personally myself as they have far better Audio Quality over the SPA phones and are pretty much similar in price.
You can view the functionality of the 6900 series HERE I do not believe them to have SSL VPN enabled on them but I could be wrong, as sometimes Cisco does LAG in updating the content on their site when they have so many updates to products coming through.
To be honest I am not sure how you are going to overcome the voice quality issue with the SPA-500 series phones, I have 4 sites complaining about the same thing and then anther two that might complain once in a while but in general they are happy... The SPA series just does not seem as good as previous models from Cisco, they are a bit of a let down from my perspective.
Where possible you should consider selling, 6900 series, 8900 series HERE or 7900 series phones, not sure if the 9000 series phones are supported yet on the UC-500 series system, but all these phones are tried and tested and have proven to be good work horses, 6900 series phones should be fairly similar to the SPA-500 series cost wise, they are a little more expensive but hey if it gets rid of the constant complaints then it is worth it, id rather take a hit on the margins then loose money down the road because of a customer not being happy and constantly taking up resources with having you constantly look into the issue.
Something for you to look at