While there is no true digital cinema IP addressing standard, there is a very popular one that was used by many theatres, including those on the Strong and Christie NOC's (Network Operation Centers), as well as some that were installed as standalones. The advantage of this numbering scheme is that once you are familiar with this scheme, finding a piece of equipment on the network is exceptionally easy. The numbering scheme works like this:
1. The scheme is based on using a dedicated subnet exclusively for the projection equipment with no, non-booth equipment attached and no DHCP server on the subnet. Simply put, if the "general, all-purpose" network used in the venue for office computers, wi-fi or the like was 192.168.1.x, the booth network would exist in a different range, such as 192.168.100.x.
2. While most small networks, particularly the "do it yourself" variety using an out-of-the-box router/AP use a subnet mask of 255.255.255.0 (sometimes known as a /24 network) that allows for 254 usable addresses in the network range, this network scheme uses a subnet mask of 255.255.254.0 (also referred to as a /23 network) that allows for up to 510 usable network addresses. For demonstration, if the base (first) address in the range used was 192.168.0.1, in the first scenario, the /24, the network would "own" all of the addresses from 192.168.0.1 to 192.168.0.254. In the second scenario, the /23 network, the range of addresses would be 192.168.0.1-254 and 192.168.1.1-254.
3. The first three octets (groups of numbers) in the address would identify the venue if it were connected to a NOC. For example, 10.17.124.x (theatre A) and 10.124.16.x (theatre B) would allow a NOC to determine which venue it was monitoring. Theatre A would "own" all addresses from 10.17.124.1 through 10.17.125.254 and theatre B would "own" 10.124.16.1 through 10.124.17.254. Theatres not connected to a NOC would generally use a non-routable address range such as 192.168.100.x. A lot of Christie, non-NOC venues use 192.168.206.x as a range as the projectors shipped with that range.
4. The last digit of the address indicates the auditorium number, thus 192.168.100.193 would indicate a piece of equipment in auditorium 3.
5. The last octet of the address indicates what piece of equipment is being addressed, for example:
All projectors in the network would be addressed as xxx.xxx.xxx.19y (where y indicates the auditorium number), thus 192.168.100.193 would indicate the projector in auditorium 3.
All servers in the network would be addressed as xxx.xxx.xxx.11y.
All automations in the network would be addressed as xxx.xxx.xxx.3y. In the case of our 192.168.100.x range for auditorium 3, this would be 192.168.100.33
All audio processors in the network would be addressed as xxx.xxx.(xxx +1).3y. Remembering that the /23 network allows for two "ranges) of addresses, this would translate to 192.168.101.33 in our example.
6. The most common pieces of equipment used in the projection booth would be defined as follows:
xxx.xxx.xxx.19y Projectors
xxx.xxx.xxx.15y Some older series 1 projectors require a secondary address for the CineCanvas, TI. This is becoming increasingly rarer.
xxx.xxx.xxx.11y Server or NAS (Christie IMB servers)
xxx.xxx.xxx.3y Automation system (ie. JNIOR, CNA or Christie automation)
xxx.xxx.(xxx+1).3y Audio processor (ie. Dolby, USL, QSC, Datasat Digital processor)
xxx.xxx.(xxx+1).15y Auditorium Switch (if a smart switch is used)
xxx.xxx.(xxx+1).2y Closed captioning device
7. Equipment common to all auditoriums in the venue would be numbered as:
xxx.xxx.xxx.1 Main gateway/router
xxx.xxx.xxx.10 Main "management" switch
xxx.xxx.xxx.25 TMS/LMS "management" interface
8. A special IP address has been reserved for the service tech when on-site. This address is generally not used within the venue but is reserved for a visiting service tech. It is xxx.xxx.xxx.15
9 Using the above-referenced scheme, an example of a projection booth whose assigned IP range was 192.168.100.x, auditorium 5 would be configured as follows:
Equipment | IP Address | Subnet Mask | Gateway |
Projector | 192.168.100.195 | 255.255.254.0 | 192.168.100.1 |
Server | 192.168.100.115 | 255.255.254.0 | 192.168.100.1 |
Automation | 192.168.100.35 | 255.255.254.0 | 192.168.100.1 |
Audio Processor | 192.168.101.35 | 255.255.254.0 | 192.168.100.1 |
Auditorium Switch | 192.168.101.151 | 255.255.254.0 | 192.168.100.1 |
Captioning Device | 192.168.101.25 | 255.255.254.0 | 192.168.100.1 |