I Need A Network Guru To Walk Me Thru This (Cross Subnet Sharing)

I have some cameras installed by a third party that we need to view. They have no problem letting my group view them, but this is a large enterprise network and I am not sure I have the networking skills to make this work reliably. Can anyone here provide some input?

Login to read this IPVM discussion.
Why do I need to log in?
IPVM conducts unique testing and research funded by member's payments enabling us to offer the most independent, accurate and in-depth information.

*** *** ********* ** **** **** **** * ******* ********* on *** *** (***** ***** ** ** *********** ** *** orange *****)?

*****, * ******* **** ******. ***, ** **** ** **** them **** ****** *** *** *** **** ****** **** ******* inside *** *** ** ********** ** *** *-* ****.

**** ** ********* * ******** ** ******* ************* ** *** VPN ************. *** ***** **** ** **** *** **** ***** of ******* *** ** ****** **** * ***** ******** (**: can *** **** ***** ****** ** *** ****** *** ** cameras **** **********, ** *** ***** ***** ******* ************ *****, etc).

**** ** ****** **** ****. **** ****** *** ** ***** with *** ******* ********* ** *** ********* *********? **** ***** be ** ********** ******, *** * ** *** ******* **** back **** *** ***** ***** ******* **** ** *** ***** that **** ****.

***** ** *** **** ***-*** ***** ***'* ** **** ******* one **** ***/** ** *********** ** ***** *** ******* ***** back *** *****. ** **** ***** *** *** ******* *****'* no "******" ******* ** *** ***** *********, ** ******.

********* ** *** **** ******* ***** *** ** *** ****** network *** *** **** ** ** **** ******* ************* ** the **** ** *** **********. *** ***** **** ** **** sure **** *** ****** ****** *** * ***** **** ** the ***... ****** ******* *** ***** **** ***** *** ******* have ** ** ******* *** *** ****** ***'** **** ** make **** *** *** *** *********** *******.

******** *** ********** ****** *** ******** *****'* ***** *** ***-*** issue. ***' ********* ******* **** *** *** ******* **** *** talking ** *** ** * ***** ***** *** *** ********* recorders ***** ***** **** *** ***** ******. (*** ******* ** certainly ******* ** ***** ****-******* ***** ******** ****** ************** ** itself.)

***** ** *** **** ***-*** ***** ***'* ** **** ******* one **** ***/** ** *********** ** ***** *** ******* ***** back *** *****.

** ***** ** ***** ** *********************, *** **** ******* ** ********.

*** ******** ****** ** ** **** ** **** * ****** from ******* *** *** ******* *** ******** *** *** **** as *** ********** ****** **** ******* *** *** *** ***. You *** ** **** **** *** ***** ****** (******** ****) too, *** **** ***** **** ** ** ****** *** *********.

***** *** **** ************ **** ***** **** *** **** *** cameras ** ** ******* ** * ********* *******. ** **** the ****? **** ** **** ** ** ******** ** * different ******* ** ****? ** ** **** **** **** ****** to **** ****/******** ***** **** *** *******? ** *** **** to *** ******* **** **** ******* ** *** **** **** interface, ***** ** **** ** * ******* *** *******/**** *****? Or ***** ******* * ******* ** ****** *********** ** **********?

*'* ** ******* **** *** ********* *** ******* **** * secondary *.***/*** ****** *********, ***** *******'* ** ****** ********** **** true *** ***, *** ** ****** *** *** ********* ******** will ** ************ *** ** *******. *** **** **** ** configure ** ****** **** ** *** ****** ********* **** ****** permits ** ****** ******* **** *** ****** ****** *-*. (** per ***** ********* *******). ********** ****** **************** ** **** ** ****** *** ********** ** ********* ***** with ***** *******.

***** *** *** ****** ****** *********.

*****, **** ***’* ******* *** ******* *** ******** **** ***** a ****** ****** ** *****. ********* *** **** *** ** isolate **** ****** ** ** **** * ***** ****** **** RTP ** ****.

****, ** ********* *** ******** **** * ****** ****** ***. One ******* *** *** ******, **********.

**** **** ***#* ****** *****, **** ** * ***** *** to ******* ***** *** *******.

** ***** ***** *** ******* ****** ** **** *** ******* VMS ******* **** ** **** ** ****** ********, *** ***** allow ***** ** ** *********** ** *** ****** ******* ***********.

** ******* * *** * **** ** ******* ** ** addresses, *** *** *** ** *** ** ********* ** **** have ****** *****, **** ** * **** ********** ****.

******* ******** *** *********** **** ** *********** **** **** ***** are ********, *** ****** ** **** ******** ***** ****** * deployment ** *****. *** ****** ** ******* ********* **** *** a *** ****** ** **********, *** ********* ***** **** **** roughly * **% ******** ******** *******.

** ******* * *** * **** ** ******* ** ** addresses

******** *** ***** *** ****** ****** ** **** ** ****** this **** ** ***** ******* ****. *** ********* ** *** diagram, *******'* **** ** ***** ***** ****.

**** *** *** **** **** *******, ****** ** ******** *** has ************.