Cisco Systems STACKT150CM manual

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 1 of 17 W hite Paper Cisco StackPower : Ef ficient Use of Power Introduction The Cisco Stac kPower ™ technolo gy is an inn ovative feature th at aggregate s all of t he available power in a stac k of switches an d manages it as one common[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 2 of 17 Cisco Stac kPower technol ogy immedia tely produces savings b y reducing the number of power supplies required per switch an d the numb er of outlets required i n the wiring cl oset. Additi onal saving s accrue from mini mizing ener[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 3 of 17 Note that a ll power available in the power sta ck is co mbined i nto one si ngle large pool of po wer, and the stac k become s a large s ingle lo ad to the po wer pool (Figure 2 ). Figure 2. Cisco Stack Power : One Power Pool, One [...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 4 of 17 Cisco Cata lyst 3750-X and 35 60-X Series Switches d o not cons ume more power than the res t of the Catal yst 3750 family of s witches, but th e power budget req uired is h igher. This hi gher budget allows each s witch to budge t [...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 5 of 17 Figure 4. Ring Topology Figure 5. Star Topology, Using an XPS The Cisco Stac kPower cables are thick but flexible, and they carry power as well as a data sig nal to provide a commu nications channel among the switches in t he power [...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 6 of 17 An XPS cable has a color b and on the cable end s as well, red o n one end and yellow on the o ther end. This c able can onl y be used to c onnect Cata lyst 3750-X or 3560 -X switch to an XPS. Note that th e connec tor with the red [...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 7 of 17 Use Case for the Cisco StackPow er Feature Figure 6. Power Stack of Four Switches The following us e cases will help you unde rstand the Cisco Stack Power technology an d its mai n features. Switches A, B, C, an d D have the fol low[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 8 of 17 Although the power stack in the example h as extra capaci ty that gets in the power pool, i t is not s ufficient to power the switch D an d PoE devices attached t o it. To get the s ystem in ba lance an d to have a pos itive power b[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 9 of 17 “show env pow er all” SW PID Serial# Status Sys Pwr PoE Pwr Watts 1A NG3K-PW R-1100W AC LIT133705 7T OK Good Good 1100/0 1B No Inpu t Power Bad N/A 235/0 2A NG3K-PW R-1100W AC LIT133705 97 OK Good Good 1100/0 2B NG3K-PW R-715W A[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 10 of 17 A maximum of 8 400W i s possi ble in a po ol of power in a stack of four switches l oaded with two 1100W power suppli es each. Obvio usly, it is e xcessive; even if the stack c onsists of four Catalysts 3750-X-48P switches requirin[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 11 of 17 Figure 8. Power Share Mode In the fol lowing scenari o, the Cisc o StackPower tech nology aggreg ates three power supplies on four switche s (1100W + 1100W + 1100W + 0W = 3300W ). The load requi rement is 500W p er switch (500W + 5[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 12 of 17 Power Share “Strict” Mode The power sharing m ode has an inherent capabili ty to oversubsc ribe itsel f in case of power supply fai lures. That is, when an i mbalance occurs b etween available p ower budgets an d allocate d pow[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 13 of 17 configu red, but it would not offline any power supply from the system. This action n eeds to be performed by an admini strator of the power stack. The following sc enario is similar to the power-shari ng mode in figure 9. The Cis [...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 14 of 17 Immedi ate load s hed occu rs when a failure could ca use the po wer stack to fai l very quickly, fo r example a mass ive power failure where m ultiple p ower supplies g o offline f or any reason a nd the availa ble power canno t s[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 15 of 17 The table sh ows the default priorities used by Stack Power that can be overwritten by an admi nistrator. As an example, a power sta ck can a ssign pri ority 2 to a switch-A, priority 10 to high priori ty ports, and pr iority 20 to[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 16 of 17 Power supply slo ts are nam ed left to ri ght, that is , power supply sl ot A in on the left and p ower supply slot B i s on the right (closest to the edge of the switch). This practi ce allows us t o distribu te power sources acro[...]

© 2012 Cisco and/o r its affiliates. All rights r eserved. This docu ment is Cisco Public Infor mation. Page 17 of 17 The recomm endation i s to perform the calc ulation of required po wer in the power stack and add th e amount o f reserved power (si ze of the large st power supply in the power stack ) and com pare the requ irement with the availa[...]