t1 module upgrades on 4331 isr gateways

[FG10]

hello,

i am trying to determine if it is possible to upgrade both the 2 pri t1 modules on both my ISR's to 4 pri t1 modules

my concern is this paticular model gateways cannot support 4 pri's 

At first glance it appears i have a free slot to add an additional t1 module but i am having a hard time

trying to determine if my 64 channel pvdm is integrated with my t1 module or if its using the 2nd module bay thus meaning i might not be able to add any additional t1 modules.

thank you in advance , any guidance would be appreciated. 

[Nithin Eluvathingal]

On ISR 4K when using T1/E1 cards, PVDM module are inserted on the NIM cards. If you are brining additional card it should   have PDVM installed to cover  the t1 channels. 

The motherboard PVDMs are supported on all Cisco 4000 Series ISRs except the ISR 4461. They can be plugged directly into the single slot on the router motherboard or into the Network Interface Module (NIM) that supports T1/E1 ports. A PVDM4 module plugged into the motherboard delivers IP-based voice services such as conferencing, media optimization, and transcoding only.

A PVDM4 module plugged into the T1/E1 NIM would be used for voice T1/E1 connectivity. Any excess channels can be reused toward other IP-based services supported on the motherboard slot. Enhanced DSP architecture accommodates a new packet-processing engine optimized for rich-media voice applications, while concurrently supporting the TDM-IP voice framework.