1 / 9

Class A jitter scenario continued

Class A jitter scenario continued. Stein Gjessing Bjornar Libaek Petter Teigen July 1. 2003. Basic scenario as yesterday, see http://www.ifi.uio.no/~steing/rpr/sim_res.ppt. Next page shows the STQ depth and Shaper D value of station 61.

kevyn-knox
Download Presentation

Class A jitter scenario continued

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Class A jitter scenario continued Stein Gjessing Bjornar Libaek Petter Teigen July 1. 2003 Basic scenario as yesterday, see http://www.ifi.uio.no/~steing/rpr/sim_res.ppt 802-17-01-nnnnn, iii_xxxxx_vv

  2. Next page shows the STQ depth and Shaper D value of station 61 • Top plot shows (in colour) how the 3% (30 Mbit/sec) class A traffic from stations 31 to 60 arrives at station 62 AND (in black) how the 1% (10 Mbit/sec) class A traffic from station 61 arrives at station 62. • Middle plot shows the shaper D value of station 61 • Bottom plot shows the STQ size of station 61 • Conclusion: Station 61 are not allowed to send A frames because the STQ is completely full! 802-17-01-nnnnn, iii_xxxxx_vv

  3. 802-17-01-nnnnn, iii_xxxxx_vv

  4. Now, shape secondary transit traffic with shaper D: • Modify condition in row 15 in table 6.29 to: • Frame = Dequeue(TX_STQ) && sendD != 0 • Not shaping secondary transit when needy (spaceInSTQ < MTU_SIZE) • Not shaping PTQResults on next page(notice that the STQ size is still only 12.5 Mbytes) 802-17-01-nnnnn, iii_xxxxx_vv

  5. 802-17-01-nnnnn, iii_xxxxx_vv

  6. Conclusions from previous page: • When shaper D shapes STQ, the STQ size increase faster (no surprise) • But shaper D still becomes negative when the STQ fills completely (because shaper D then does not shape STQ any more, shaper D is then only decreased) 802-17-01-nnnnn, iii_xxxxx_vv

  7. Now, increase STQ-size • Based on suggestion from Mike Takefman • STQ is now increased from 12.5KB to 256KB. • Still shaper D shapes STQ • Next page shows • Top: Station 31 to 61 packets arrival at station 62(notice the nice horizontal 10Mbit/s traffic (black line) from station 61) • Bottom: STQ utilization in station 61 • Not shown: shaper D, which oscillates around normal values, and never becomes negative. 802-17-01-nnnnn, iii_xxxxx_vv

  8. 802-17-01-nnnnn, iii_xxxxx_vv

  9. Conclusion • With large STQs and shaping of STQ (by shaper D), class A jitter from station 61 is eliminated! • Still some jitter in the class A traffic from stations 31 to 60To be further investigated 802-17-01-nnnnn, iii_xxxxx_vv

More Related