1. v1.0 - 20050426 Telecommunications Industry AssociationTR-30.3/08-12-017 Lake Buena Vista, FL December 8 - 9, 2008

2. TIA921B Algorithm – An Update Alan Clark

3. Interfering Source Model 2 1 No packets Packet Parameters: - p12, p21 = Transition probabilities (forward) - p12, p21 = Transition probabilities (reverse) - k = MM update frequency Low value of k, low value of p21 … e.g. VoIP High value of k, high value of p21 … e.g. TCP

4. Interfering Source Model Model reverse flow –TCP – assume model generates primary packet stream estimate packet volume in reverse direction for normal ACKs –VoIP – assume symmetric packet flow –IPTV – assume unidirectional packet flow

5. Base Model - 1 Estimated Queuing Delay Interfering Source Interfering Source Stream Limits for queuing delay in each direction AND common delay (i.e. shared queue) Overflow model (i.e. queue length limit) Loss Model

6. Base Model - 2 At time t: For each interfering source Probability of being in packet burst = p(b) Decide on a packet burst length Decide on the position within the packet burst Compute contribution that preceding part of packet burst added to queuing delay

7. Issue 1 If next “t” is close to previous then both events could have occurred in the same packet burst Add: if t within previous estimate of packet burst length then use previously calculated burst parameters

8. Issue 2 If multiple test stream packets are closely spaced they will add to the queuing delay (i.e. self congestion) Add: incorporate contribution of this packet to queuing delay

9. Model + Queue Limit Interfering Source Interfering Source Interfering Source Interfering Source Test Stream

10. + Queue Limit Interfering Source Interfering Source Interfering Source Interfering Source Test Stream Model + Queue Limit Interfering Source Interfering Source Interfering Source Interfering Source Test Stream