Interlogix NVR 21 (S/P) User Manual - Manual (Page 152)

Appendix C: Port forwarding information
146 TruVision NVR 21(S/P) User Manual
Many router manufacturers also offer guides on their websites as well as including
documentation with the product.
On most routers the brand and model number is located on or near the serial number
sticker on the bottom of the device.
If you cannot find any information for your particular router, please contact your router
manufacturer or internet service provider for further assistance.