arfur mo Posted August 9, 2010 Posted August 9, 2010 just an idea and i'm not sure if suitable for your site, but could you reduce bandwidth loading by using a form of motion detection if the cameras support it? idea being only to transmit the changed pixels not the whole frames. i don't know of kit that would do this of the bat, but i'm sure it's out there as yours won't be the only application required for it in the world, and if its not i might sit down a design it . Arfur If you think education is difficult, try being stupid!!!!
james.wilson Posted August 9, 2010 Author Posted August 9, 2010 That's called conditional refresh and is used in codes like mpeg4 and h264. But that brings additional decoding issues. The display machines are also upscaling the images I don't want to overload them. Also those codes have additional latency which I don't want. But thanks anyway. I have found out that most switches do what i need as long as I avoid the bottom end ones. securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Alpat Systems Posted August 9, 2010 Posted August 9, 2010 Hi James, I'd suggest a Layer 3 switch before the server (basically a Layer 3 switch is more like a router, so you can set rules for incoming/outgoing traffic) Connect the switch to the server via fibre, fibre NIC cards are common practice in bandwidth hungry applications. All modern Layer 3 can be linked together via cascade ports (these do not take up an Ethernet connection) and allow central administration so upgrading is easy, this is assuming the switches are close together. Alternatively the best practice is to have a fibre backbone between all switches. My preference of switches would be: Cisco Nortel HP Forgot to add. If the server is struggling with 1 fibre NIC, more can be added. Load balancing can be setup with the server OS
james.wilson Posted August 9, 2010 Author Posted August 9, 2010 just the man The servers only have 2 seperate pci busses so i plan to configure the I/O on one buss, and the the ethernet on the other. As they are old style parralel pci they have a hard limit of 133Megabytes per second. So assuming i can get close to the theoritical limit of gigabit then i plant to stay with copper rather than fibre. If the servers were more manly then id agree that a fibre backbone would be the way to go, but i fear its a waste of budget given the other limitations. Im planning on using this securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Alpat Systems Posted August 9, 2010 Posted August 9, 2010 Hi James, First thing is to split the project into 2: Network Infrastructure Server Infrastructure. Firstly.....Is the current network purely for IP CCTV traffic, or Data/IP CCTV If Data/IP CCTV what applications are they currently running / any future plans they have. (This affects what network security may be required on the switches) What does there current network consist of: i.e number of current switches (or maybe hubs??) print servers, computers, etc... What is the total number of current cameras / future requirements? Next server infrastructure. What is the current spec of the server/servers where the IP CCTV software is? What is the IP CCTV software? What OS is it running? Budget? Is there on-site IT support?
james.wilson Posted August 9, 2010 Author Posted August 9, 2010 What is the current spec of the server/servers where the IP CCTV software is? 4 x (ie seperate) quadcore xeons, 4Tb per server (raid 5), 8 gig ram What is the IP CCTV software? Our own linux based (x64) What OS is it running? linux Budget? Hard one to answer, but we are starting a £25k upgrade to the cameras (8 x ip cams replacing coax) Is there on-site IT support? Yes but this is our network, we have nowt to do with them, or cams, our switches, our fibre, our client pcs, etc etc I hate IT depts securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Alpat Systems Posted August 9, 2010 Posted August 9, 2010 Hi James, Just to clarify, the servers only have PCI slots and not PCI-e? I know in the past you could purchase Quad Port NIC PCI cards, but I've not seen one in ages. Its looking like the biggest stumbling block you currently have is the servers There is an expensive way of compressing bandwidth by using acceleration servers/hardware
james.wilson Posted August 9, 2010 Author Posted August 9, 2010 agreed. But accross the hardware i dont think i will have a problem with this, assuming the switch will give me 20-30 mb a sec securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Alpat Systems Posted August 9, 2010 Posted August 9, 2010 agreed. But accross the hardware i dont think i will have a problem with this, assuming the switch will give me 20-30 mb a sec According to the specs the switch will handle 12.8Gbps, are you basing 20-30mbps on 8 cameras @25fps (what size is the image?), as it seems quite low? The switch is only a web managed switch, not a true managed switch (i.e no routing)
james.wilson Posted August 9, 2010 Author Posted August 9, 2010 there is a total of 50 cameras currently. Some are axis 223m's, 221's 209's 207's etc. I plant to run the vga ones at 10ish fps, and the megapixels at about 4fps. And i was meaning megabytes per second not mega bits. securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
Recommended Posts
Archived
This topic is now archived and is closed to further replies.