IXIA OC12c/OC3c Load Modules
This chapter provides details about OC12c/OC3c family of load modules specifications and features.
The OC12c/OC3c family of load modules implements Optical Carrier interfaces that may run at OC12 or OC3 speeds. Both interfaces operate in concatenated mode, as opposed to channelized mode. Different numbers of ports and interfaces are available for the different board types. The features available for these load modules are included in the Port Features by Port Type matrix, which is located on the ixiacom.com website under Support/User Guides/Spreadsheets.
One of the modules in this family, the LMOC12c, is shown in the following figure.
Figure: LMOC12c Load Module

Part Numbers
The part numbers are shown in the following figure. Items without a Price List Names entry are no longer available.
Load Module | Price List | Description |
---|---|---|
LMOC12c/LMOC3c |
LMOC12c |
2-port multilayer OC12c/OC3c SR-1 POS/SDH, 1310nm multimode |
LMOC12cSM |
2-port multilayer OC12c/OC3c SR-1 POS/SDH, 1310nm singlemode |
Specifications
The load module specifications are contained in the following table. The limitations of -3, Layer 2/3 and Layer 7 cards are discussed in Ixia Load Modules.
LMOC12cLMOC12cSM | |
---|---|
# ports |
2 |
-3 Card Available |
N |
Layer2/Layer3 Card Available? |
N |
Layer 7 Card Available |
N |
Data Rate |
1-100% of OC12/OC3 speeds (See note 3) |
Connector |
SC-Singlemode or Multimode |
Capture buffer size |
16MB |
Captured packet size |
OC3: 49 - 5,120 bytesOC12: 49 - 15,500 bytes (See note 1) |
Streams per port |
255 |
Flows per port |
N/A |
Preamble Size: min-max |
N/A |
Frame size (transmit): min-max |
34-65,536 bytes (See note 4) |
Frame size (receive): min-max |
12-65,536 bytes (See note 5) |
Inter-frame gap: min-max |
N/A |
Inter-burst gap: min-max |
1ms - 85secs |
Inter-stream gap: min-max |
1ms - 85secs |
Latency |
20ns resolution (See note 2) |
- Captured Packet Size Note: At 100% line rate. Smaller values are possible at lower line rates.
- Requires that packets be larger than 70 bytes when operating at full line rate.
-
Correct data rates can only be maintained with a minimum number of packets, depending on packet size. For OC12 operation, the numbers of packets are required for the indicated ranges of packet sizes:
OC12 Minimum Number of Packets Packet Size Minimum Number of Packets per Stream 45 or less
30
46 - 47
8
48 - 54
7
55 - 63
6
64 - 84
5
85 - 129
4
130 - 199
3
200 - 499
2
500+
0
- The maximum frame size depends on the type of header and PPP negotiation. The maximum frame size is 64k bytes although beyond 8192 bytes, the data is repeated.
- 12 byte frames cannot be received back-to-back. A 34 byte frame is required to receive back-to-back frames.
For OC3 operation, the numbers of packets are required for the indicated ranges of packet sizes:
Packet Size | Minimum Number of Packets per Stream |
---|---|
34 or less |
4 |
35 - 64 |
3 |
65 - 274 |
2 |
275+ |
0 |
Port LEDs
Each OC12c/OC3c port incorporates a set of 4 or 6 LEDs, as described in the following table.
LED Label | Usage |
---|---|
LOS |
Red during Loss of Signal. |
LOF |
Red during Loss of Frame. |
Error |
Red on any POS error. |
Tx |
Green while data is transmitted. |
Rx |
Green while data is received. |
Trig |
Follows the state of the Trigger Out pin. |
Trigger Out Values
The signals available on the trigger out pins for all cards in this category are described in the following table.
Pin | Signal |
---|---|
1 |
Port 1: 10 ns high pulse for each packet matching User Defined Statistic 1 |
2 |
Port 2: 10 ns high pulse for each packet matching User Defined Statistic 1 |
3 |
Port 1: Low during transmit of frame, otherwise high |
4 |
Port 2: Low during transmit of frame, otherwise high |
Optical Specifications
The optical characteristics for the OC12c/OC3c cards are described in the following table.
Specification | OC12c/OC3c Multimode | OC12c/OC3c Singlemode |
---|---|---|
Average Output PowerMinimum/Maximum |
-19 dBM/-14 dBM |
-15 dBM/-8 dBM |
Transmit Center WavelengthMinimum/Maximum |
1270 nm/1380 nm |
1293 nm/1310 nm |
Receive Center WavelengthMinimum/Maximum |
1270 nm/1380 nm |
1200 nm/1550 nm |
Receive SensitiveMinimum/Maximum |
-26 dBM/-14 dBM |
-28 dBM/-5 dBM |
Safety |
Led based |
Class 1 Laser |
Statistics
Statistics for OC12c cards, under various modes of operation may be found in Statistics for OC12c/OC3c Modules.