NVR Recording and Network Considerations vicon-security.com Video Security Design Workshop: NVR Recording and Network Considerations Vicon A&E Summit 2011

New Technology – New Issues Newest Generation of IP Video Systems Presents New Challenges: Systems are entirely IP They include megapixel cameras with significantly higher picture resolution Ease of connectivity is facilitating more cameras-per-system Need for More Resources!

How Network and Storage are Affected Demands of IP video systems put an increased load on: The network carrying the video The storage holding those recordings Analogies to describe the situation: Cars on a road heading to work Water in a pipe heading to a pool

Bandwidth = Traffic A road can handle only so many cars. A network can carry only so many bits. To move more cars, we need more lanes. To move more bits, we need more bandwidth.

Storage = Parking Lot Parking lots can hold only so many cars. Hard drives can hold only so many video files. Once the lot is full, parking more cars requires: Expanding the parking lot Having some cars leave to make room for new cars Once a hard drive is full, we can either: Add more storage capacity Remove older video files to make room for new recordings (Shorten the number of days video is kept)

Water Pipe Analogy Hose = Bandwidth Swimming Pool = Storage Puppy = ???

Design Considerations For Each Camera: How many FPS is really necessary? What resolution is required? For Storage: How much is required given above camera requirements and number of days storage For Network: How to best use technology to create an efficient system? Work with IT to maximize the network traffic and optimize storage

IP Cameras on the Network IP camera-based systems require more bandwidth Megapixel cameras need even more Consistent, reliable system performance requires network planning Recommendation: Video transmission may consume up to 70% of total network bandwidth (i.e., 1000 Base/T network can provide about 70 Mbps for video transportation)

Parameters that Affect Bandwidth Resolution The higher the resolution, the higher the bandwidth: Frame Rate 1-30 fps per camera; higher FPS  higher bandwidth. Motion Type Higher motion (activity) in the picture (i.e., a casino floor) uses more bandwidth than medium motion (i.e., an office space) Compression Format H.264, MPEG-4, M-JPEG have varying requirements

Expected Bandwidth for a Single Frame

Network Configuration How many cameras can the network support? Output from the switch = sum of all camera outputs

Data Flow: Analog Cameras, DVR and Workstation System Server Nucleus Analog Cameras Analog Signal iSCSI Display Path: DVR to Workstation Hybrid DVRs Playback Path: DVR to Workstation Storage Recording: Done on the DVR

Data Flow: IP Cameras, NVR and Workstation System Server Nucleus IP cameras and Encoders Display Path: Camera to Workstation iSCSI NVRs Recording Path: Camera to NVR Storage Backup NVRs Playback Path: NVR to workstation

Data Flow: IP Cameras & Virtual Matrix Display Controller System Server Nucleus IP cameras and Encoders Display Path: Camera to VMDC and to Monitor iSCSI NVRs Recording Path: Camera to NVR Storage Backup NVRs Playback Path: NVR to VMDC and to Monitor

Data Flow: IP Cameras & Several VMDCs System Server Nucleus IP cameras and Encoders Display Path: Camera to VMDC and to Monitor through another VMDC iSCSI NVRs Recording Path: Camera to NVR Storage Backup NVRs Playback Path: NVR to VMDC and to Monitor through another VMDC

Basic Calculations Connecting 10, 20, or 50 cameras on the network? Assuming each camera outputs 2 Mbps, then… 10 cams X 2 Mbps = ~ 20 Mbps 20 cams X 2 Mbps = ~ 40 Mbps 50 cams X 2 Mbps = ~ 100 Mbps SO When using a 100 Mbps switch 35 cams X 2 Mbps = ~ 70 Mbps = 70% capacity This is the maximum recommended number of cameras.

Daisy Chain versus Star Topology Cascading Switches How many network switches are needed? Systems with many IP cameras require multiple switches Daisy Chain versus Star Topology Which should you use? Main Switch 1 2 3 4 5 Switch 1 Switch 2 Switch 3 Switch 4

Daisy Chain Topology Assuming 100 Mbps switches 18Mbps 6Mbps 50Mbps Too Many Mbps 18Mbps

Star Topology Assuming 100 Mbps switches 50Mbps 50Mbps 50Mbps Possibly too many Mbps

Star Topology - Explanation Using a 1000 Mbps (1 Gbps) switch: IP cameras use a 100 Mbps network card Connecting to a 100/1000 Mbps switch will utilize 1000 Mbps (1 Gbps) going out to the PCs Whether the cameras can connect from smaller switches at 100 Mpbs to central switches at 1000 Mbps all depends on the accumulated bandwidth Remember to make sure each and every switch has enough bandwidth to support its in/out needs!

Using 1 Gbps Switches The main switch can output 1Gbps

Individual Streams Every user gets an individual stream from the camera. Data is fully acknowledged to protect from losing information. Bottleneck on one viewer doesn’t affect the others. 2 Mbps Wireless bridge 3X2 Mbps ≈ 6 Mbps Wireless access point Switch 2 Mbps 2 Mbps 4 Mbps

Multicasting Streams Each camera sends only one stream to the network Special switch provides a copy of the stream to PCs who request it Everybody gets the same stream regardless of their supported bandwidth Multicast is UDP and not acknowledged 2 Mbps Wireless bridge 2 Mbps Wireless access point Switch 2 Mbps 2 Mbps 4 Mbps

Switch Backbone and Output Every switch has a certain specification A 16 port switch with 1Gbps ports cannot support a full 1Gbps through each port simultaneously. Its “Backbone” is the total throughput capacity. The more professional the switch, the stronger the backbone. High end switch systems usually connect the central switches with a special connection or fiber to create a central backbone. “Stacking” switches

Pure Gigabit Stack

Points to Remember What are the critical design points in the network? Evaluate the expected bandwidth from each camera keep in mind the number of concurrent users per camera. Each switch’s output (to the next switch or NVR) must not exceed 70% of maximum bandwidth Using the Star topology, add central switches with higher bandwidth. Remember, every port on the switch has its own bandwidth, so if two workstations are connected to two different ports, each has its own 100 or 1000 Mbps. In very high traffic network, invest in a strong central stack of switches with a strong backbone