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Frequently asked questions

  • Network Products
    • Do UTC switches support Port Limiting?

      Do UTC switches support Port Limiting?

      Answer:

       

      Answer:

       

      Yes. We call it Rate Limiting. The following switches have this function:

       

                  GE-DSG-244/GE-DSSG-244 Series

                  GE-DS-242-PoE

                  GE-DS-82/GE-DS-82-PoE

                  GE-DSH-73/GE-DSH-82/GE-DSH-82-PoE

    • How can you configure ''Rate Limiting'' on a switch?

      How can you configure ''Rate Limiting'' on a switch?

      Answer:

       

      Answer:

       

      The following sequence show the process for rate limiting:

       Rate limiting should not be confused with Port Speed. The latter fixes the port speed to 10/100/1000 Mbps or Automatic. Rate limiting establishes a specific limit.

      UTC Switch advantages:

       

      Many switches active this setting via complex command line functions. As show above UTC switches use a simple to understand, simple to use graphical user interface allow for setting and viewing of all port status.

    • How does the cable distance effect available bandwidth for the MCE- Coax

      How does the cable distance effect available bandwidth for the MCE- Coax

      Answer:

       

      Answer:

       

       Cable distance will always have an effect on any signal transmission. The longer the cable the greater the available bandwidth loss.  The loss from about 5 meters (16 feet) to 1600 meters (about 1 miles) is about 30%. So starting with 100Mbps, the total available bandwidth is about 70Mbps. Using the 54% figure for usage bandwidth would result in about 35Mbps available for your data transmission.

    • How many cameras can I connect to one single switch?

      How many cameras can I connect to one single switch?

      Answer:

       

      Answer:

       

      That depends on the bandwidth of the individual signals used as input to the ports. The bandwidth of switches are fixed, generally at 10Mbps, 100Mbps and 1 Gbps.

       

      As a general rule, overheads within a switch will consume about 46% of the total bandwidth leaving 54% for data, (in this case data is would be the same as video). For a 100Mbps switch the resulting bandwidth is 54Mbps. For 1G, the resulting bandwidth would be 540Mpbs.

       

      To know the number of cameras you must first know the individual bandwidth of the individual cameras. So a camera requiring 5 Mbps can have 5 cameras on a single 100Mbps port. However it is strongly recommended that only a single device is connected to one port.

    • How many IP cameras can the MCE-Coax carry.

      How many IP cameras can the MCE-Coax carry.

      Answer:

       

      Answer:

       

      That depends on several factors. The first is determining the amount of actual bandwidth available. In IP transmission part of the total bandwidth is taken up on various overheads. In general a conservative figure is to allow about 54% of the total available bandwidth for data transmission. So a 100Mbps would yield about 54Mbps for data. Next is the primary direction the data is traveling. A camera transmitting to a server would be considered Down Stream transmission.

      Once the bandwidth of the camera is determined you simply divide that figure into the result bandwidth. For example: if a camera requires 2Mbps of bandwidth and you have 54Mbps available, 27 cameras can theorically be carried on the MCE-Coax.

    • What are the advantages of using a Ring Topology?

      What are the advantages of using a Ring Topology?

      Answer:

       

       Answer:

       

      In creating ring networks for security networks we create redundancy. Because the ring is sending data unidirectional the system will become redundant. Whenever there is a break in one of the cables the network will automatically recover itself by using the network in a different direction.

       

      The recovery times using the standard protocol configurations such as Spanning tree protocol and rapid spanning tree protocol is between 3 and 60 seconds. By using the proprietary protocol X-Ring on the GE-DSH hardened switches from UTC we can provide a recovery of the signal of less than 20 milliseconds.

       

      20 ms = 1 frame from a surveillance camera

       

      You can create a ring network of up to 50 nodes in one ring without losing recovery time. If you create bigger rings the recovery time of the signal will slightly increase.

    • What are the main advantages of SNMP ?

      What are the main advantages of SNMP ?

      Answer:

      Network Management is all about keeping the network up and running, monitoring, and controlling network devices using conventional network technology.

      The Simple Network Management Protocol is quite simple because it is easy to understand. It is this simplicity that serves as a key reason for its widespread acceptance.

       

      Standardized protocol: SNMP is the standard network management protocol for TCP/IP networks. Internet Protocols are open, nonproprietary standards developed through voluntary efforts by the Internet community, so is the SNMP that is actively maintained and all future enhancements to SNMP are based on existing protocol standards.

      Universal acceptance: All major vendors support SNMP. All SNMP-managed devices use the same type of management interface to support a common set of network management information. 

      Portability: SNMP is independent of operating system and programming language. The functional design of SNMP is also portable and it defines a core set of operations that must function identically in all devices that support SNMP. 

      Lightweight: SNMP facilitates the addition of management capability to a device without impacting the operation of the device or its performance. SNMP management may be added to a network device with very little increase in workload and demand on system resources.  

      Extendibility: SNMP is a core set of operations that remain the same on all managed devices. SNMP has the capability of supporting any type of information on any type of device that may be part of any type of computer network. 

      Widely deployed: SNMP is one of the most popular protocols in the protocol suite that every vendor is aware of. This popularity serves as one dominant factor for its wide deployment by the vendors.

      The following switches have this function:
      - GE-DSG-244/GE-DSSG-244 Series
      - GE-DS-242-PoE
      - GE-DS-82/GE-DS-82-PoE
      - GE-DSH-73/GE-DSH-82/GE-DSH-82-PoE

    • What are the main advantages of Storm Control ?

      What are the main advantages of Storm Control ?

      Answer:

      Storm-control is very useful for all switches. It allows you to set limits for Broadcast and Multicast traffic. When those limits are exceeded, traffic of that type is blocked on the interface until the storm has passed.

      Typically, broadcast and multicast traffic can the network down as it gets perpetually forwarded in a loop. With storm control the damage is limited, hopefully enough to allow LAN access to continue with reduced performance.

      The following switches have this function:
      - GE-DSG-244/GE-DSSG-244 Series
      - GE-DS-242-PoE
      - GE-DS-82/GE-DS-82-PoE
      - GE-DSH-73/GE-DSH-82/GE-DSH-82-PoE

    • What are the main advantages of VLAN’s ?

      What are the main advantages of VLAN’s ?

      Answer:

      The main advantages of VLAN (Virtual LAN) are listed below.

      • Broadcast Control: Broadcasts are required for the normal function of a network. Many protocols and applications depend on broadcast communication to function properly. Broadcasts can consume all available network bandwidth. A layer 2 switched network is in a single broadcast domain can restrict broadcasts to that VLAN network only. A layer 3 device (typically a router) is used to segment a broadcast domain.

      If we segment a large LAN to smaller VLANs we can reduce broadcast traffic as each broadcast will be sent on to the relevant VLAN only.

      • Security:
      VLANs provide enhanced network security. In a VLAN network environment, with multiple broadcast domains, network administrators have control over each port and user. A malicious user can no longer just plug their workstation into any switch port and sniff the network traffic using a packet sniffer. The network administrator controls each port and whatever resources it is allowed to use.

      VLAN’s can separate network traffic logically within a switch so that devices connected to one VLAN cannot communicate with another VLAN.

      • Cost: Segmenting a large VLAN to smaller VLAN’s is cheaper than creating a routed network with routers because normally routers costlier than switches.

      The following switches have this function:
      - GE-DSG-244/GE-DSSG-244 Series
      - GE-DS-242-PoE
      - GE-DS-82/GE-DS-82-PoE
      - GE-DSH-73/GE-DSH-82/GE-DSH-82-PoE

    • What is a layer 2+ switch and what are the advantages.

      What is a layer 2+ switch and what are the advantages.

      Answer:

       

      Answer:

       

      The first thing you should know is that layer classifications are not standardized. For video transmission the most important (+) feature is contained with multicasting, which helps to reduce bandwidth and increase transmission efficiency on the network. Many switch manufacturers are claiming to support multicasting but only support IGMP snooping. This is only half of the requirement. Full multicasting requires both snooping and querying.

    • What is average latency of UTC switches?

      What is average latency of UTC switches?

      Answer:

       

      Answer :

       

      Average latency is measured by using a packet generator. The average latency within UTC switches is 290.000 ns. (using packet size 1518bytes).

    • What is Port limiting?

      What is Port limiting?

      Answer:

      Answer:

       

      Port limiting, as the name indicates is the function of limiting the amount of bandwidth traffic that can be used at any given individual port. It is used to control traffic and restrict a user from taking up an excessive amount of system bandwidth. Port Limiting is applied to both input and outputs (called Ingress/Egress).

       

      In practical applications this feature can be used to restrict the amount necessary to match the requirements of a device, for example a device that only requires 5 Mbps. In a client application a secondary security viewer to a video security system that doesn't require the need to see either full resolution images or high refresh rates.

    • What is switch fabric?

      What is switch fabric?

      Answer:

       

      Answer: 

       

      The switch fabric can be thought of as the switches' internal bandwidth. It indicates how quickly signals travel within the switch. The same rules that apply to single ports should also apply to the switch fabric. Where this becomes important is when switches are stacked. This is when the output of one switch, which we will call a node, is connected to another switch, which we will call a backbone, which also receives inputs from several other switches.

       

      In this case the total bandwidth of all signals received from the various nodes to the backbone should not exceed 54% of the backbone switches' "switch fabric".

       

      In general a backbone switch will contain 24 ports. UTC's 24 port switches have switch fabrics of 48 and 64 Gbps. UTC's 8 port switches have switch fabrics of 16Gbps.

    • What PoE standard is supported in UTC's network products range?

      What PoE standard is supported in UTC's network products range?

      Answer:

      Answer:

       

      The PoE being used with all the Power over Ethernet application is the 802.3AF standard. This standard supports up to 15.4 watt in terms of power.

      (The  802.3AT high powered PoE standards is coming soon)

    • Which IEEE standards are supported by UTC's network switches?

      Which IEEE standards are supported by UTC's network switches?

      Answer:

       

      Answer: 

       

      All The protocols indicated below are part of UTC's switches. This way they can be compatible to different switch manufacturers:

       

      IEEE 802.3 10Base-T
      IEEE 802.3u 100Base-TX/100Base-FX
      IEEE 802.3z Gigabit SX/LX
      IEEE 802.3ab Gigabit 1000T
      IEEE 802.3x Flow Control and Back pressure
      IEEE 802.3ad Port trunk with LACP
      IEEE 802.1d Spanning tree protocol
      IEEE 802.1w Rapid spanning tree protocol
      IEEE 802.1s Multiple spanning tree protocol
      IEEE 802.1p Class of service
      IEEE 802.1Q VLAN Tagging
      IEEE 802.1x Port Authentication Network Control
      IEEE 802.1ab LLDP
      RFC 768 UDP
      RFC 793 TFTP
      RFC 791 IP
      RFC 792 ICMP
      RFC 2068 HTTP
      RFC 1112 IGMP version 1
      RFC 2236 IGMP version 2
      IEEE 802.3af Power over Ethernet

  • Fiber
    • Are there any power consumption restrictions on the number of cards that can be fitted into the DFR rack?

      Are there any power consumption restrictions on the number of cards that can be fitted into the DFR rack?

      Answer:

      A.  No.  The DRF rack can be equipped with any combination of cards that will fit in the space available (viz. 14 slots for a single PSU, 11 slots if a 2nd

      back-up PSU is fitted).

       

    • Can I mix 8 bit and 10 bit Video Transmission systems?

      Can I mix 8 bit and 10 bit Video Transmission systems?

      Answer:

      A.  No, not on the same fiber.   8 bit transmitters must always be paired with 8 bit receivers, and 10 bit transmitters with 10 bit receivers. But you can, of course, fit both 8 bit and 10 bit units in the same rack.

    • Do you offer a product for ''up-the-coax'' telemetry systems?

      Do you offer a product for ''up-the-coax'' telemetry systems?

      Answer:

      A.  No, not in the IFS Fiber range.   Most CCTV camera manufacturers who use ‘up-the-coax’ telemetry will usually offer a second choice, for example RS485 or RS422.

       

      For the rare occasion where this is not offered one possibility is to deploy the Legacy IFS ‘up-the-coax’ product VT/VR1505.   Note that the rack card version of this product can be fitted within a DFR rack using the DFR-R3-1 adaptor plate.

    • How many channels can I send over one fiber?

      How many channels can I send over one fiber?

      Answer:

       

      Answer:

       

      We offer the following combination of different channels:

       

      Video

      Video + Data

      Video + Audio

      Video + Contact Closure

       

      In 1, 2, 4, and 8 video channel configurations.

      (coming soon: CWDM system to send up to 128 channels of 10 bit digitally processed analog video channels over one fiber!!)

    • My camera telemetry is stated as being 2-wire RS485, but there is no return data (i.e. the telemetry is from keyboard to camera only). Should I set the transmission equipment for 2-wire RS485 data?

      My camera telemetry is stated as being 2-wire RS485, but there is no return data (i.e. the telemetry is from keyboard to camera only). Should I set the transmission equipment for 2-wire RS485 data?

      Answer:

      A.  No, strange as it may seem.  The problem with a ½ duplex 2-wire RS485 connection is that it will always be looking for a return transmission from the camera, and may respond to spurious noise even when there is none intended.  This will be fed back onto the keyboard data network and may corrupt the telemetry to all other cameras.

       

      Set up the transmission equipment for either 4-wire RS485 data or RS422 data (it really doesn’t matter which), connect the keyboard to pins 6 & 7 and camera to pins 2 & 3 for the outgoing data path, and just ignore the return path.

    • There are no 2 fiber versions of these products. Why not?

      There are no 2 fiber versions of these products. Why not?

      Answer:

      A.  Historically it was more expensive to produce a product which provided two-way transmission on one fiber than on two.   Consequently we have always offered both 1 and 2 fiber versions of these products in our Legacy Fiber Options and Legacy IFS product families.

       

      The bi-di optics used in the IFS Fiber range of products are sufficiently cost effective to eliminate this price difference and hence 2 fiber versions are longer necessary or provided.  This simplifies both the logistics and installation of the project.

    • What about terminations?

      What about terminations?

      Answer:

      A.  The principle of data terminations is that the data bus should be fitted with a termination at its remote ends, but not at intermediate points.  Therefore if you have a keyboard connected to a number of IFS Fiber transmitters (in a rack, for example) in daisy-chain fashion, then terminate the far-end transmitter at the end of the chain (by setting SW1 to ON), but not at intermediate transmitters.

    • What are the relative performances of 8 bit and 10 bit Video Transmission?

      What are the relative performances of 8 bit and 10 bit Video Transmission?

      Answer:

      The relative performances of each are summarised in the table below:

       

                                                                              8 bit                10 bit

      Number of TV Lines                                      480                 560

      Equivalent Analogue Bandwidth                  6MHz              7MHz 

      Signal/Noise (weighted)                               55dB               60dB+

      Differential Gain                                              2%                  <1%

       

      8 bit Video Transmission is primarily intended for CCTV Surveillance applications whilst the higher quality 10 bit Video Transmission can also be used for Broadcast TV applications as well as CCTV Surveillance applications.

       

    • What do we mean by the term ''Optical loss budget''?

      What do we mean by the term ''Optical loss budget''?

      Answer:

       

      Answer: 

       

      "Optical loss budget" defines the differences between Transmitter Power and Receiver Sensitivity. It is one of the most important specifications in determining the distance a signal can travel over fiber. 

       

      Usually calculating optical loss budget is a simple math.

       

      Transmitter power  - Receiver Sensitivity  = Loss Budget

       

      Other factors in the system will deduct from the available loss budget. They are:

       

      1. Multimode or Single mode
      2. Type of cable (50um or 62.5um)        
      3. Number of Connectors: Deduct 1db per connector.
      4. Number of Splices: Deduct .5 db per splice
    • What do you mean by Digital Video Transmission?

      What do you mean by Digital Video Transmission?

      Answer:

      A.  All our IFS Fiber Transmission products employ digital encoding for transmission over the fiber.  The analogue video input signal amplitude is sampled (measured) at a very high rate, each sample amplitude being converted into a binary digital number for transmission over the fiber.  At the receiving end, this number is converted back into an analogue amplitude to re-constitute the original analogue video signal.

    • What is the benefit of Digital Video Transmission over Analogue?

      What is the benefit of Digital Video Transmission over Analogue?

      Answer:

      A.  Because each sample is transmitted as a pure integer number, for example 57 (but in binary digital form) it will always be received perfectly (i.e. there is no possibility of 57 being received as 56.9 or 57.1, as can happen with analogue transmission).   Therefore, unlike analogue transmission, digital signal quality does not degrade with increasing link distance.

    • Why do the Multimode Video Systems have a maximum range which is much shorter than predicted from their Loss Budgets?

      Why do the Multimode Video Systems have a maximum range which is much shorter than predicted from their Loss Budgets?

      Answer:

      A.  The maximum range of fiber link is determined from either the loss budget or fiber bandwidth, whichever is the smaller.  Taking the 8-video channel multimode DFVMM8-T and DFVMM8-R pair as an example, this has a specified loss budget of 12dB at 1310nm in 62.5um fiber which would predict a maximum range of at least 12km.

       

      However multimode fiber bandwidth restricts the maximum range to about 1km, as a result of the high transmission bandwidth of this product.  Products with a lesser number of video channels require less fiber bandwidth, and hence their maximum ranges are greater. But even single channel video systems have a bandwidth limited range which is considerably less than the loss budget limit.

       

      Generally speaking fiber bandwidths are about 50% greater in 50um than in 62.5um multimode fiber.  As a rule of thumb the following maximum ranges apply:

       

      # Video Channels               62.5um Range           50um Range

      1                                                       4km                                6km                                               6km

      2                                                       3km                             4.5km

      4                                                       2km                                3km

      8                                                       1km                             1.5km

       

      Please note that these distances are as a result of limitations of the fiber and not the transmission system.   The maximum range of single-mode systems is loss budget limited, hence is very much larger and not affected by the number of video channels.

    • Your products are either 8 bit or 10 bit Video. What does this mean?

      Your products are either 8 bit or 10 bit Video. What does this mean?

      Answer:

      A.  As mentioned in an earlier question, each sampled video amplitude is converted into a binary digital number for transmission over the fiber.  8 bit or 10 bit refers number of digital bits used in this conversion, and hence the accuracy.  8 bit numbers can represent decimal numbers from 0 to 255, therefore the conversion accuracy is 0.5 in 256 (since the actual sample amplitude will be rounded up or down to the nearest whole number, so the maximum conversion error is 0.5), i.e. approx 0.2%.  This is equivalent to a S/N ratio of about 55dB.  10 bit numbers can represent decimal numbers from 0 to 1023, a conversion accuracy of 0.5 in 1024, or about 0.05% (66dB).

       

      A second factor is that the sampling frequency is increased with 10 bit Video, meaning that higher Analogue Bandwidths can be accommodated.

    • Your units use Digital Video Transmission. Is this the same as IP Video?

      Your units use Digital Video Transmission. Is this the same as IP Video?

      Answer:

      A.  No.   Although our units employ digital encoding for transmission over the fiber, both the input and output signals are analogue.  In addition the digital signal is uncompressed and intended for transmission over a dedicated fiber to a dedicated receiver, thus forming a point-to-point transmission link.   IP Video uses digital compression to allow the signal to be transmitted over existing IP networks.

       

      For a comprehensive range of IP Video products, please refer to the Networks Products section of this website.