1 / 19

Inverse Multiplexing over ATM (IMA)

Inverse Multiplexing over ATM (IMA). ATM Switch. Objectives. Define the motives for the development of IMA Describe basic IMA operation Define the role and describe the features of the IMA netmods and port card Explain DS3 and OC-3 channelization

yeriel
Download Presentation

Inverse Multiplexing over ATM (IMA)

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. Inverse Multiplexing over ATM (IMA) ATM Switch

  2. Objectives • Define the motives for the development of IMA • Describe basic IMA operation • Define the role and describe the features of the IMA netmods and port card • Explain DS3 and OC-3 channelization • Configure an IMA interface to support IMA groups

  3. Bandwidth, Cost and IMA OC-3 155 MbpsOC-12 622 Mbps Cost $ DS3 45 Mbps Break even point between purchasing multiple DS1s or one DS3 is between 6 to 8 DS1s DS1 1.5 Mbps – IMA Market Bandwidth

  4. DS1 Links ATMNetwork ATMNetwork Congestion Congestion Before IMA • Congestion • Connection Admission Control (CAC) failures • Over-subscription

  5. Throughput After IMA • Implement IMA and the switches “see” the multiple links as one bigger link (e.g., 6 Mbps below) • The IMA group understands that there are multiple links and allows portions to be added or deleted “on the fly” IMA Groups ATMNetwork ATMNetwork 6 Mbps Logical Link

  6. PHY PHY PHY PHY PHY PHY IMA Details • Tx: Cells sent across links round robin • Rx: Cells recombined to a single stream Link 1 ATM SwitchFabric ATM SwitchFabric IMA Group IMA Group Link 2 Received from ATM Layer Passed to ATM Layer Link 3 IMA Virtual Link

  7. + PHY PHY PHY PHY PHY PHY ICP Cell • ICP cell shown as striped • Takes up some bandwidth • One ICP cell per IMA frame • Usually small percentage overhead (single-digits) Link 1 ATM SwitchFabric ATM SwitchFabric IMA Group IMA Group Link 2 Received from ATM Layer Passed to ATM Layer Link 3 IMA Virtual Link

  8. + 50% PHY PHY PHY PHY 50% PHY PHY Lost Link Recovery ICP cell detects the broken link and informs the group to redistribute traffic 33% ATM SwitchFabric ATM SwitchFabric IMA Group IMA Group 33% Received from ATM Layer Passed to ATM Layer 33% IMA Virtual Link

  9. IMA IMA IMA Hardware Netmods • DS1/E1: 8 ports; 1-8 groups (up to 8 links/group) • Ch DS3: 3 ports; 84 virtual DS1s; 42 groups per netmod (up to 8 links/group) IMA IMA Point-to-Point Applications Port Card • Ch OC-3: 168 virtual DS1s/126 E1s; 42 groups per port(up to 8 links/group) DS1 TNX-210 ADM ASX-4000 Channelization DS1 DS1 Rest of ATMNetwork IMA Channelization ADM DS3 OC-3 ADM ADM DS1 IMA function with aggregation

  10. DS3 Channelization Example • 28 individual DS1s • 1 physical interface (DS3) divided into 28 virtual interfaces (DS1s) ChannelizedDS3 port Netmod

  11. OC-3 Channelization Example STS-1 DS3 ChannelizedOC-3 port Port Card STS-1 DS3 28 individual DS1s STS-1 DS3

  12. IMA Configuration Menus ATM SWITCH:-> interfacesima ATM SWITCH:interfaces ima-> ? group> The group directory link> The link directory potential> The potential directory ATM SWITCH:interfaces ima group-> ? current Display current statistics delete Delete an IMA group interval Display interval statistics modify Modify IMA group attributes new Create a new IMA version 1.1 group number Display number of configured IMA groups reset Reset an IMA group show Display IMA group configuration test> The test directory total Display total statistics

  13. Configuration Syntax for New IMA Group ATM SWITCH:interfaces ima group-> new ? [[-index] <ImaIf>] Index (default: IMA1) [[-symmetry] <symmetry>] Symmetry (default: symOper) [[-minnumtxlinks] (1..32)] Min Num Tx Links (default: 1) [[-minnumrxlinks] (1..32)] Min Num Rx Links (default: 1) [[-netxclkmode] <clockmode>] NE Tx Clock Mode (default: ctc) [[-tximaid] (0..255)] Tx Ima Id (default: 1) [[-txframelength] <framelength>] Tx Frame Length (default: m128) [[-diffdelaymax] <integer>] Diff Delay Max (default: 25) [[-alphavalue] (1|2)] Alpha Value (default: 2) [[-betavalue] (1|2|3|4|5)] Beta Value (default: 2) [[-gammavalue] (1|2|3|4|5)] Gamma Value (default: 1) [[-imalinks] <list of ImaCapableIf>] List of IMA Links (default: "") [[-autoreset] (disabled|enabled)] Automatically Reset (default: enabled) [[-name] <text>] IMA Group Name (default: "") [[-autotestpattern] (disabled|enabled)] Automatic Test Pattern Status (default: disabled) [[-autoResetFalseDelay] (disabled|enabled)] Automatic Reset on false delay (default: disabled) [[-trapFalseDelay] (disabled|enabled)] Send trap on False Delay (default: disabled) [[-maxFalseDelayTrap] <integer>] Max false delay for Trap (default: 15) [[-maxFalseDelayReset] <integer>] Max false delay for Auto Reset (default: 25)

  14. DS1 Netmod IMA Group Configuration ATM SWITCH:interfaces ima group-> new ima1 -imalinks "1d1 1d2“ ATM SWITCH:interfaces ima group-> show NE NE Tx Tx Max Cfg MinTx MinRx Clock Ima Frame Diff Group Ver Symmetry Links Links Mode ID Len Delay Alpha Beta Gamma (ms) IMA1 v11 symOper 1 1 ctc 1 m128 25 2 2 1 ATM SWITCH:interfaces ima group-> number Number of configured IMA groups: 1 ATM SWITCH:interfaces ima link-> show Link Group 1D1 IMA1 1D2 IMA1

  15. Ch DS3 Netmod IMA Group Configuration ATM SWITCH:interfaces ima group-> new ima1 -imalinks 1b1(1);1b1(2);1b1(3);1b1(4) ATM SWITCH:interfaces ima group-> show NE NE Tx Tx Max Cfg MinTx MinRx Clock Ima Frame Diff Group Ver Symmetry Links Links Mode ID Len Delay Alpha Beta Gamma (ms) IMA1 v11 symOper 1 1 ctc 1 m128 25 2 2 1 ATM SWITCH:interfaces ima group-> number Number of configured IMA groups: 1 ATM SWITCH:interfaces ima link-> show Link Group 1B1(1) IMA1 1B1(2) IMA1 1B1(3) IMA1 1B1(4) IMA1

  16. Ch OC-3 Port Card IMA Group Configuration ASX-4000:interfaces ima group-> new ima1 –imalinks 2c1[1](2,2);2c1[1](2,3) ASX-4000:interfaces ima group-> show NE NE Tx Tx Max Cfg MinTx MinRx Clock Ima Frame Diff Group Ver Symmetry Links Links Mode ID Len Delay Alpha Beta Gamma (ms) wIMA1 v11 symOper 1 1 ctc 1 m128 165 2 2 1 pIMA1 v11 symOper 1 1 ctc 1 m128 165 2 2 1 ASX-4000:interfaces ima group-> number Number of configured IMA groups: 2 ASX-4000:interfaces ima link-> show Link Group 2C1[1](2,2) wIMA1 2C1[1](2,3) wIMA1

  17. PVC Configuration Example ATM SWITCH(ASX-200BX) 1C1 C D IMA Group 1 A B SCP SCP UNI Device UNI Device 1D4 C D IMA Group 5 A B SCP SCP Other Switch(ASX-200BX)

  18. PVC Configuration Commands ATM SWITCH:connections channel-> new ? [-iatmif] <AtmIf> Input AtmIf [-ivpi] <integer> Input VPI [-ivci] <integer> Input VCI [-oatmif] <AtmIf> Output AtmIf [-ovpi] <integer> Output VPI [-ovci] <integer> Output VCI : ATM SWITCH:connections channel-> new 1C1 0 100 ima1 0 100 ATM SWITCH:connections channel-> new ima1 0 100 1c1 0 100 ATM SWITCH:connections channel-> show ima1 Input Output AtmIf VPI VCI AtmIf VPI VCI ServCat Protocol Name IMA1 0 3 IMA1 0 3 UBR oam N/A IMA1 0 4 IMA1 0 4 UBR oam N/A IMA1 0 5 1CTL 0 249 nrtVBR fsig_ctl N/A IMA1 0 16 1CTL 0 250 nrtVBR fsig_ctl N/A IMA1 0 100 1C1 0 100 UBR pvc ATM SWITCH:connections channel-> show 1c1 Input Output AtmIf VPI VCI AtmIf VPI VCI ServCat Protocol Name 1C1 0 3 IMA1 0 3 UBR oam N/A 1C1 0 4 IMA1 0 4 UBR oam N/A 1C1 0 5 1CTL 0 33 nrtVBR fsig_ctl N/A 1C1 0 16 1CTL 0 34 nrtVBR fsig_ctl N/A 1C1 0 100 IMA1 0 100 UBR pvc

  19. Summary • Defined the motives for the development of IMA • Described basic IMA operation • Defined the role and describe the features of the IMA netmods and port card • Explained DS3 and OC-3 channelization • Configured an IMA interface to support IMA groups

More Related