PVDM4-128 on Router Motherboard vs Install in T1/E1 Card

[johnlloyd_13]

hi,

i'm going to prepare and configure a voice 4k ISR router. this is to replace an old 29xx router.

just wondering what's the best approach/practice for installing a PVDM4-128 card: install directly on the router motherboard or install in the T1/E1 NM card?

the old 29xx router currently has an ISDN line connected.

also just considering if in case router will move to SIP and disco the ISDN. was thinking the PVDM-128 might be removed by another engineer if he want to use the NM slot i.e. a switch module or extra gig ports.

[marce1000]

                                                Looks like both may apply

 - Following : https://www.cisco.com/c/en/us/products/collateral/routers/4000-series-integrated-services-routers-isr/data_sheet_c78-728307.html , ref Table 1 :

  >... 

PVDM4-128(=)

On-board motherboard or T1/E1 module slot

128-channel high-density voice DSP module, or spare