# Phone call problems with  Q64001. Version R74A

**URL:** https://forum.sierrawireless.com/t/phone-call-problems-with-q64001-version-r74a/8216
**Category:** Legacy AirPrime modules
**Created:** [September 29, 2015, 12:36pm UTC](https://forum.sierrawireless.com/t/phone-call-problems-with-q64001-version-r74a/8216 "2015-09-29T12:36:55Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![RamonHS](https://avatars.discourse-cdn.com/v4/letter/r/b3f665/32.png) [@RamonHS](https://forum.sierrawireless.com/u/RamonHS)
#### Post date: [September 29, 2015, 12:36pm UTC](https://forum.sierrawireless.com/t/phone-call-problems-with-q64001-version-r74a/8216/1 "2015-09-29T12:36:55Z")

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Hi all,

One of our customers is experiencing phone call problems with this device, many calls are not progressing…we see in our network a dissconnect message from device, is this version old R74A old? should we upgrade this version?

thanks

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### Author: ![mlw](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/mlw/32/3706_2.png) [@mlw](https://forum.sierrawireless.com/u/mlw)
#### Post date: [September 30, 2015, 12:50pm UTC](https://forum.sierrawireless.com/t/phone-call-problems-with-q64001-version-r74a/8216/2 "2015-09-30T12:50:06Z")

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Hi,

The version of firmware is obviously old but is still valid, there is a limit as to how far you can upgrade the units since Sierra stopped producing releases for it a couple of years ago (because it was so old). You need o contact your commercial channel to get the latest if you really wan to upgrade it (R7.47 I think was the last version).

Regards

Matt