1 x OneWay Session

1xOneWay sessions are setup between two or more probes and are used to measure/supervise the one-way QoS performance between the sender probe and receiver probe(s). Multiple receiver probes are possible if the 1xOneWay session is configured to use multicast addressing.

Further, synchronization is required to enable measurement of one-way propagation delay and the appropriated synchronization will be setup between the interacting probes, e.g. the receiver probe(s) will perform clock synchronization toward the sender probe.

The figure below shows a 1xOneWay unicast measurement between two probes. Synchronization is setup between the probes and result is reported to the SDC through the control-plane (Ctrl/SSH).

Available encapsulations for unicast data streams are: UDP, TCP, GRE, SCTP, ICMP and RTP, and the following codecs are available for VoIP streams (using RTP): G.711, G.723.1, G.729, G.729a, GSMEfr and GSMHr.

The following metrics are measured and reported for 1xOneWay sessions:

• One-way Propagation Delay
• One-way Propagation Delay Variation (Jitter)
• One-way Packet Loss
• One-way Packet Reorder
• One-way Duplicated Packets
• One-way Bandwidth & Packet-Rate
• MOS & R-Value (VoIP)

Moreover, result data is reported from a session with a configurable interval. The amount of reported data is also configurable, and is spanning from basic packet statistics up to information about every single packet sent and received.

1xOneWay session can be configured to use multicast addressing, in this case one or more receiver can be configured to measure the same multicast channel. The measured and reported metrics are the same as for 1xOneWay unicast sessions. The figure below shows 1xOneWay multicast measurement between three probes. The two receivers perform synchronization toward the sender probe.

Available encapsulations for multicast data streams are: UDP and RTP.