It's no problem setting up your MISP card to be used as a BRI-Line that communicates through the PRI card. I use this all the time. But make sure you configure 2 numbers at each channel so that the Videosystem can have more than 1, 3 or 5 channels.
But here is my config, and I think you have to setup the DSL first, then assign the numbers via TSP. The config below is used on a Tandberg Videoconferencing system...
LD 27
REQ prt
TYPE dsl
DSL 4 1
DATE
PAGE
DES
NACT
TN 4 0 0 1
DES S0
CUST 0
CTYP SILC
OPT BRIL
MISP 3
MODE NTAS
B1CT VCE DTA
B2CT VCE DTA
LDN NO
XLST 0
MTEI 20
MCAL 16
MTSP 8
LAPD 1
PRID 2
PDCA 2
FDN
EFD
HUNT
EHT
TGAR 1
NCOS 0
SCPW
SGRP 0
CAC_MFC 0
CLS UNR ICDD CDMD MRD UDI ABDD PGND BRTD
DATE 4 FEB 2004
Then assign numbers.
REQ prt
TYPE tsp
DSL 4 1
OPT
USID 0
MPHC NO
SUPL_SVC AO6
DN 25555 0
CT VCE DTA
MCAL 4
CLIP YES
PRES YES
COLP NO
TRANS NO
FEAT HTD FND SFD CFTD MWD FBD HBTD CFXD DNO3 DNDY
SSRV_ETSI
DN 25554 0
CT VCE DTA
MCAL 4
CLIP YES
PRES YES
COLP NO
TRANS NO
FEAT HTD FND SFD CFTD MWD FBD HBTD CFXD DNO3 DNDY
SSRV_ETSI
DFDN 25555
i2007