TY - JOUR
T1 - Modeling the effect of wavelength selective switch latency on optical flow switching performance
AU - Shakeri, Ali
AU - Wang, Xue
AU - Razo, Miguel
AU - Alabarce, Miquel Garrich
AU - Oki, Eiji
AU - Yamanaka, Naoaki
AU - Fumagalli, Andrea
N1 - Funding Information:
This research was supported in part by NSF grants No. CNS-1111329, CNS-1405405, CNS-1409849, ACI-1541461, and CNS-1531039. M. Garrich thanks the Brazilian Ministry of Communications (FUNTTEL/ FINEP) and CNPq (grant 312047/2015-0).
Publisher Copyright:
© 2018 Optical Society of America.
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Optical networks are well suited to enable massive data exchanges between datacenters. Elephant data flows can be routed over custom provisioned and dedicated lightpaths (optical flows) while other (mice) flows, which are routed by electronic switches, are unaffected. In some solutions, wavelength-selective switch (WSS) devices are employed in the optical nodes to physically and individually route each lightpath toward its destination. WSS devices take time to be switched and consequently delay the lightpath setup completion time. In this paper, the authors present three approximate Markov chain models to account for three different WSS service policies. These models estimate the expected lightpath setup and teardown time across an optical node that makes use of WSS devices. The first and more conventional policy (model) assumes that each setup and teardown request is handled individually, while the other two policies (models) assume that groups of setup and/or teardown requests are handled together by the WSS. The models' estimates are compared against the results obtained from a computer-based simulator, where both analytical models and simulator account for experimentally measured WSS response times. The simulator is also used to investigate the end-to-end lightpath setup time across an arbitrary mesh network. Results obtained from the models and simulator show that the group-based service policies outperform the conventional policy at high loads. The group-based policies are especially useful in the presence of lightpaths that are frequently set up and have relatively short holding time (i.e., short duration of elephant-optical flows).
AB - Optical networks are well suited to enable massive data exchanges between datacenters. Elephant data flows can be routed over custom provisioned and dedicated lightpaths (optical flows) while other (mice) flows, which are routed by electronic switches, are unaffected. In some solutions, wavelength-selective switch (WSS) devices are employed in the optical nodes to physically and individually route each lightpath toward its destination. WSS devices take time to be switched and consequently delay the lightpath setup completion time. In this paper, the authors present three approximate Markov chain models to account for three different WSS service policies. These models estimate the expected lightpath setup and teardown time across an optical node that makes use of WSS devices. The first and more conventional policy (model) assumes that each setup and teardown request is handled individually, while the other two policies (models) assume that groups of setup and/or teardown requests are handled together by the WSS. The models' estimates are compared against the results obtained from a computer-based simulator, where both analytical models and simulator account for experimentally measured WSS response times. The simulator is also used to investigate the end-to-end lightpath setup time across an arbitrary mesh network. Results obtained from the models and simulator show that the group-based service policies outperform the conventional policy at high loads. The group-based policies are especially useful in the presence of lightpaths that are frequently set up and have relatively short holding time (i.e., short duration of elephant-optical flows).
KW - Circuit switching
KW - Markov chain model
KW - Optical networks
KW - Wavelength selective switch
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U2 - 10.1364/JOCN.10.000924
DO - 10.1364/JOCN.10.000924
M3 - Article
AN - SCOPUS:85058527195
VL - 10
SP - 924
EP - 935
JO - Journal of Optical Communications and Networking
JF - Journal of Optical Communications and Networking
SN - 1943-0620
IS - 12
ER -