Observer nTAPs : Observer nTAPs : nTAP Models : Aggregator nTAPs : Copper-to-Optical Aggregator
Copper-to-Optical Aggregator
Decide where to place the nTAP and physically mount it, if desired. Depending on the form factor purchased, this may be in a drive bay, rack mount bracket, or wherever it is most convenient.
Keep the nTAP horizontal for efficient heat dissipation.
The network adapter you connect to the Analyzer side of the Copper-to-Optical Aggregator nTAP must have auto-negotiation disabled, otherwise no traffic will be passed to that network adapter. This also means the network adapter must support the ability to disable auto-negotiation; not all third-party network adapters support this. However, all Gen3 capture card models can enable and disable auto-negotiation.
A Conversion Aggregator TAP is used when the analyzer communicates over a different topology than the network (copper vs. optical). It merges full-duplex links into a single stream for transmission to the analyzer ports. The TAP receives a full-duplex signal and sends it out as a half duplex signal. The Link and Analyzer sides negotiate their connections independently so that each is optimized. The Link (network) side's signal may be the same speed or slower than the Analyzer side; it cannot be faster.
This is true whether you use copper or optical connections for the Analyzer ports. For instance, if your Link side is at 100 Mb and your analyzer connection is 1 Gb, the TAP sends data to the analyzer at 1 Gb, known as up-converting, and there is no chance of over-subscribing the buffer. If your Link side is 1 Gb, then your connection to the analyzer must also be 1 Gb. It cannot be 100 Mb because the analyzer cannot receive the traffic from the Link side fast enough.
When traffic comes in to Link A, two copies are made in the TAP. One copy is sent out Link B to the switch and the other copy is joined with a copy of the traffic from Link B and sent out the Analyzer AB ports to the analysis device(s). A similar thing happens with traffic that comes in Link B. Two copies are made. Due to how the TAP is designed, it is not possible for traffic from the Analyzer side to pass to the Link side.
Figure 23: Cabling the Copper-to-Optical Aggregator
Caution: Before you temporarily break the link between the device of interest and the network, you may want to shut down access to that device and notify users of the down time.
1. Ensure that power is connected to the nTAP. You can provide power to one or both power supply sockets on the back panel of each nTAP. Connecting both sockets to different external power sources provides fail-safe power redundancy for the Analyzer side.
2. Disconnect the cable from your device (typically a switch) and connect it to Link B. You want to connect Link B first because it negotiates its network speed first, and Link A then must use the same speed as Link B. If your link is part of a failover or redundancy arrangement, then connect the failover device to Link B.
3. Connect your network device (or primary device in a failover arrangement) to Link A.
4. Connect the Analyzer ports on the TAP to the receiving ports of the monitoring device. See Are the analyzer ports “send only”?
Note: The role of the buffer is to absorb traffic spikes of over 50% full-duplex bandwidth saturation (100% with both sides combined), because the analyzer’s single-receive interface cannot receive the traffic fast enough to keep up at line rate. For more details about the Aggregator TAP’s buffer, see Choosing the Aggregator TAP buffer size
Choose either copper or optical cables to connect to your analyzer. If an SFP is present, its corresponding copper Analyzer port is disabled. The optical ports only support a 1 Gb network connection. For details about the split ratios, which are set at the factory before the TAP is shipped, seeDetermining the best split ratio for you.
All Optical TAP devices contribute to optical attenuation. See a fuller discussion of it in Attenuation.
Technical specifications
This section lists the dimensions, power requirements, supported media, and environmental requirements.
This action lists the dimensions, power requirements, supported media,and environmental requirements.
Both power connectors are located on the back panel, along with the model information and serial number.
Power requirements
AC Input
100-240V 50/60Hz 0.5A
Operational Voltage
5V (+10%/-5%, < 100 mV ripple)
Operational Current
Typical: <= 1.8 amps; Max: <= 2.8 amps
Power Dissipation
Typical: 8 watt; Max: 14 watt
Environmental requirements
Temperature range
32° - 113° F/0° - 45° C (Operating): The fanless cooling design relies on conduction and convection from the nTAP casing. Your installation environment must provide enough cool airflow for the nTAP casing to maintain an operating temperature less than 113°F/45°C.
-52° to +185°F / -47° to +85°C (storage)
35-85% (non-condensing)
Supported media
Link ports
Straight-through RJ-45 cable or crossover cable
Copper Analyzer ports
Straight-through RJ-45 cable or crossover cable
SFP/XFP Analyzer ports
1000BaseSX, 850nm, Multimode, LC Connector; 62.5 or 50 µm fiber
1000BaseLX, 1310nm, Multimode or Single-mode, LC Connector; 62.5, 50, or 8.3 µm fiber
Wavelength tolerance ranges
Multimode 850/1300 (Dual-window)
+/- 20 nanometers
Single-mode 1310 or 1550 (Dual-window)
+/- 40 nanometers
Buffer size
256 MB, 512 MB, 1 GB (depending on TAP)
5.62 in/14.28 cm
1.15 in/2.93 cm
7.79 in/19.78 cm