What are the Differences Between Ethernet BERT and Throughput Tests?
Ethernet Throughput is the preferred, framed Ethernet/IP test because it measures BER and service KPIs (frame loss, latency, delay, etc.), while Ethernet BERT measures only bit errors, and exists mainly for interoperability with non‑VeEX testers.
Ethernet Throughput is the preferred, framed Ethernet/IP test because it measures BER and service KPIs (frame loss, latency, delay, etc.), while Ethernet BERT measures only bit errors, can't detect frame loss, and exists mainly for basic interoperability with other non‑VeEX testers.
| Feature | Throughput | BERT |
|---|---|---|
| Traffic type | Ethernet/IP framed | Ethernet/IP framed |
|
Proprietary fields |
Yes | No |
| BER measurement | Yes | Yes |
| Frame loss detection | Yes | No |
|
Frame-related KPIs |
Yes |
No |
| Latency / delay | Yes | No |
|
Round-Trip Delay (RTD) |
Yes | No |
| One-Way Delay (OWD) | Yes | No |
| RFC2544 / Y.1564 alignment | Yes | No |
| Pattern sync required | No | Yes |
| VeEX to VeEX testing | Recommended | Not recommended |
| VeEX to Other Vendor testing | ⚠️ Limited | Intended use |
| VeEX to Loopback device | Yes | Yes |
Ethernet Throughput Test
The Ethernet Throughput application generates framed Ethernet/IP traffic and measures service‑level performance with greater detail. The test packets used in Throughput tests include proprietary fields in the Ethernet payload to enable comprehensive statistics collection, which can create compatibility issues when testing between instruments from different vendors.
The throughput test provides:
- Throughput rate
- Frame count & frame loss
- Round‑trip delay / one‑way delay
- Latency & jitter
- Bit errors and BER (yes—BER is included)
- KPIs aligned with RFC2544, Y.1564 / VSAM, and framed Ethernet testing
Key Technical Characteristic
- Uses VeEX proprietary payload fields to track individual frames, order and timing
- Same mechanism used by RFC2544, VSAM (Y.1564), and Throughput
- Works best VeEX‑to‑VeEX or VeEX‑to‑loopback scenarios
When to Use Throughput Test
Default and recommended test
- Turn‑up, service validation, SLA testing
- Lab, field, manufacturing, and acceptance testing
- Any scenario where Ethernet/IP KPIs matter
- Point-to-point testing between two VeEX test sets
- Point-to-loopback testing between VeEX or other vendor test set
Ethernet BERT
The Ethernet BERT application also sends Ethernet/IP framed traffic, but without VeEX proprietary information fields. It behaves like a pure bit‑pattern test inside Ethernet frames. Ethernet BERT is not the recommended test.
Important: Ethernet BERT still uses Ethernet frames, so it shall not be confused with unframed PHY‑level BER test (Layer 1 BERT or Lane BERT).
BERT Provides:
- Basic throughput rate
- Bit errors (provided that proper test pattern sync can be attained)
- Bit Error Rate (BER)
No frame‑based or service KPIs are available:
- No frame loss identification or count
- No frame sequence issues
- No latency or delay
- No data throughput KPIs
Key Technical Characteristic
- No proprietary signature or information fields
- Requires test pattern synchronization
- Pattern sync between different vendors may require trial‑and‑error payload selection
- Since the BERT can't identify dropped (missing) frames, it may show that all is OK on a real switched network with problematic links. Errors on an intermediary link won't be detected because the errored frames are discarded by the receiving switch.
When to Use BERT
A last resort for special interoperability cases only, such as:
- In point-to-point tests, when the test set at the far end of the link is not VeEX.
- Both ends transmit and receive independently.
- When proprietary test payloads, with extra overhead information (custom vendor signature), would otherwise make the test incompatible.