1 Washington WASHINGTON UNIVERSITY IN ST LOUIS Fred Kuhns - 3/15/2016 Allocate and free code option instance, NPE resources and interface bandwidth. Manage interfaces –Get interface attributes: {{ifn, type, ipaddr, linkBW, availBW},...} –If peering then get peer’s IP address –Allocate aggregate interface bandwidth Allocate external port number(s) Define meta-interfaces –Substrate adds line card filter(s) –Slice may specify minimum BW Associate queues with meta-interfaces –Substrate has to map meta-interface numbers used in TCAM filters to the corresponding local addresses Manage queue parameters, get queue length –threshold, bandwidth (weight) Slice-Centric View MI 1 := { myIP, Port 1 } MI n := { myIP, Port n }... Slice x Fast path Slice x TCAM (Filters) stats SRAM block qiqi... q0q0 wrr MI 1 qkqk... qjqj MI 2... qlql qjqj MI m qparams MI 1 (tunnel) MI 2 (tunnel) MI n (tunnel) BW 1,min BW 2,min BW n,min q GPE GPE Slice x control application wrr DRAM block max Buffers substrate slice state VLAN max weights Manage TCAM filters –add, remove, update, get, lookup –Substrate remaps slice ids (qid, fid, mi, stats) to global identifier One-time or periodic statistics –Periodic uses polled or callback model Read and write SRAM –Substrate verifies address and length –Extended to also support DRAM memory qlen, threshold, weight

2 Washington WASHINGTON UNIVERSITY IN ST LOUIS Fred Kuhns - 3/15/2016 FP slice 1 Mapping Slice Queue BW to Queuing Weights q 1n... Slice Interface and Queue Allocations: {Port, BW, QList}; Qlist = {{qid, weight, threshold},...} q 10 q 11 wrr q 2m... FP slice 2 q 20 q 21 NPE GPE FP 1 GPE FP 2 linkBW wrr BW 11 BW 21 BW 11 + BW 21 = BW 1 BW 1 Physical Port (Interface) Attributes: {ifn, type, ipaddr, linkBW, availBW} ifn : Interface number type: {Internet, Peering} Operations: get_interfaces() get_ifattrs(ifn) get_ifpeer(ifn) alloc_ifbw(ifn,bw) LC qid in 0...n-1 qid in 0...m-1 ipAddr

3 Washington WASHINGTON UNIVERSITY IN ST LOUIS Fred Kuhns - 3/15/2016 NPE FP slice 1 qid in 0...n-1 FP slice k qid in 0...m-1... q 11 w q 12 w 12 q 1n w 1n q p1 w p1... q p2 w p2 q pm w pm... wrr BW s,k VLAN Single Interface Example wrr q xsn... q xs1 q xs2 Sched NPE1 q psn... q ps1 q ps2 Sched GPE1 q BE... Ingress Map fp:MI to Q {dip, dp, pr} wrr Sched CP q sn... q s1 q s2... wrr q GPE q CP Sched I1 Egress src addr proto port/icmp LC interface 1 NPE... Total weight for all slices (i) and queues (j) ≤ max weight for scheduler s (W s )... BW NPE1,GPE1 local delivery and exception q w,GPE1 wrr GPE... LC Ingress –One queue per slice with reserved bandwidth (really one per scheduler) –One queue for best effort traffic to each GPE –One scheduler for CP with queues for reserved traffic plus BE LC Egress –At least one scheduler for each physical interface –One queue for each active slice with MI defined for the associated scheduler –One best effort queue for each board (GPE, CP, NPE?) NPE –Slice binds queues to meta-interfaces, hence physical interfaces –Slice either reserves BW on a physical interface or it is assigned the minimum –Substrate assigns a per interface maximum weight for each slice Substrate sets scheduler rates according to aggregate allocations –Manage scheduler rates to control aggregate traffic to interfaces and boards. minimum weight = 1 MTU sized packet Sched s,k BW I1 slice’s allocated BW scheduler min rate

4 Washington WASHINGTON UNIVERSITY IN ST LOUIS Fred Kuhns - 3/15/2016 q 1jn... q 1j0 q 1j1 wrr q 2jm’... q 2j0 q 2j1 NPE FP 1 GPE FP 2 linkBW wrr BW 11 BW 12 BW 2 LC FP slice 1 qid in 0...n-1 FP slice 2 qid in 0...m-1 IP 2 q 1jn’... q 1j0’ q 1j1’ wrr q 2jm’... q 2j0’ q 2j1’ FP 1 GPE FP 2 linkBW wrr BW 1 IP 1 to interface 1 to interface 2 Two Interface Example, Setting Queue Weights Slice i, meta-interface j, qid k and scheduler s.

5 Washington WASHINGTON UNIVERSITY IN ST LOUIS Fred Kuhns - 3/15/2016 Formulas Slice i, meta-interface j, QID k and scheduler s. scheduler fastpath meta-interface qid