Layer 1–4 loopbacks (MAC address, IP address, and port swapping) enable remote QoS testing for Ethernet, IP/MPLS, and triple-play services. You can establish a loopback by using any of the following parameter combinations:
- Source or destination address
- TCP/UDP port
- Service level
You can run loopbacks in-band or out-of-band so that customer traffic continues to flow while you test selected streams.
The device supports the following loopback types:
- Local (private) loopback—Loops back all traffic that matches the configured loopback type (Iometrix L1, EXFO L2, EXFO L3, or Custom).
- Remotely controlled loopback—Loops back traffic when the unit receives a predefined frame type (JDSU/Acterna™, Sunrise™).
© 2026 Cisco and/or its affiliates. All rights reserved.
For more information about trademarks, please visit: Cisco trademarks
For more information about legal terms, please visit: Cisco legal terms
For legal information about Accedian Skylight products, please visit: Accedian legal terms and trademarks