RibMgmt » History » Version 2
Lan Wang, 04/18/2014 04:22 AM
| 1 | 1 | Junxiao Shi | # RIB Management |
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| 2 | |||
| 3 | **RIB Management** is a module of [[Management|NFD Management protocol]]. |
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| 4 | It provides: |
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| 5 | |||
| 6 | * commands to register and unregister routes |
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| 7 | * commands to advertise and withdraw prefix with a routing protocol |
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| 8 | |||
| 9 | RIB Management commands are published in namespace `ndn:/localhost/nfd/rib`. |
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| 10 | |||
| 11 | ## Route |
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| 12 | |||
| 13 | A **route**, or a **routing entry**, indicates that contents under a certain name prefix may be available via a certain face. |
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| 14 | |||
| 15 | A route contains: |
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| 16 | |||
| 17 | * Name prefix |
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| 18 | * nexthop FaceId |
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| 19 | * cost |
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| 20 | * route inheritance flags |
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| 21 | |||
| 22 | **Cost** indicates the preference among multiple routes with same Name prefix. |
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| 23 | The nexthop face on a route with lower cost is preferred. |
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| 24 | Unlike IP routing, the nexthop face to use is decided by forwarding strategy. |
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| 25 | Routing cost is a suggestion to strategy; strategy MAY consider routing cost when making forwarding decisions. |
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| 26 | |||
| 27 | ### Route inheritance |
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| 28 | |||
| 29 | Each route can have two route inheritance flags: |
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| 30 | |||
| 31 | * CHILD\_INHERIT: indicates that this route may be used even if a longer prefix is matched. |
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| 32 | This flag applies on a single route. |
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| 33 | * CAPTURE: indicates that no shorter prefix can be used; overrides CHILD\_INHERIT. |
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| 34 | This flag applies on the prefix: if any route of a prefix has this flag, the prefix will have this flag. |
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| 35 | |||
| 36 | Example: |
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| 37 | |||
| 38 | Name prefix | nexthop FaceId | CHILD\_INHERIT | CAPTURE |
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| 39 | ------------|----------------|----------------|--------- |
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| 40 | / | 1 | yes | no |
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| 41 | / | 2 | no | no |
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| 42 | /A | 3 | yes | no |
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| 43 | /A/B/C | 4 | yes | no |
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| 44 | /D | 5 | yes | yes |
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| 45 | /D | 6 | yes | no |
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| 46 | |||
| 47 | * Interest /A/P can go to face 1 and 3. |
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| 48 | * It cannot go to face 2, because that route has CHILD\_INHERIT=no. |
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| 49 | * Interest /A/B/C/Q can go to face 1, 3, and 4. |
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| 50 | * Interest /D/R can go to face 5 and 6. |
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| 51 | * It cannot go to face 1, because one of the routes on /D sets CAPTURE=yes. |
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| 52 | * Interest /S can go to face 1 and 2. |
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| 53 | |||
| 54 | ## Control Commands |
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| 55 | |||
| 56 | [[ControlCommand]] **management-module**: `rib` |
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| 57 | |||
| 58 | ### Register a route |
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| 59 | |||
| 60 | **command-verb**: `register` |
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| 61 | |||
| 62 | This command adds a route to the RIB. |
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| 63 | |||
| 64 | ControlParameters fields: |
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| 65 | |||
| 66 | * Name (required) |
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| 67 | * FaceId (optional) |
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| 68 | * Flags (optional) |
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| 69 | * Cost (optional) |
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| 70 | * ExpirationPeriod (optional) |
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| 71 | |||
| 72 | FaceId is the FaceId returned in [[FaceMgmt|Face Management]]. |
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| 73 | If FaceId is omitted or is set to zero, it is implied as the requesting face (self registration). |
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| 74 | If face does not exist, the command fails with code 410. |
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| 75 | |||
| 76 | Flags is an inclusive OR of route inheritance flags. |
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| 77 | CHILD\_INHERIT=1, CAPTURE=2. |
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| 78 | It defaults to CHILD\_INHERIT. |
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| 79 | |||
| 80 | Cost defaults to zero. |
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| 81 | |||
| 82 | ExpirationPeriod indicates the duration (in milliseconds) in which this route is effective. |
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| 83 | After ExpirationPeriod is elapsed, or when the face fails, the route is removed. |
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| 84 | ExpirationPeriod defaults to Infinity when FaceId is omitted or is set to zero; otherwise, it defaults to 1 hour. |
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| 85 | |||
| 86 | 2 | Lan Wang | If a route of same Name and FaceId exists, its Flags and Cost are updated, and its lifetime is extended to now + ExpirationPeriod. |
| 87 | 1 | Junxiao Shi | |
| 88 | If the command succeeds, \<Body> in ControlResponse block contains updated ControlParameters. |
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| 89 | |||
| 90 | * Name: Name prefix |
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| 91 | * FaceId: nexthop FaceId |
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| 92 | * Flags: inclusive OR of route inheritance flags |
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| 93 | * Cost: routing cost |
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| 94 | * ExpirationPeriod: remaining lifetime (in milliseconds) |
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| 95 | |||
| 96 | ### Unregister a route |
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| 97 | |||
| 98 | **command-verb**: `unregister` |
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| 99 | |||
| 100 | This command removes a route from the RIB. |
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| 101 | |||
| 102 | ControlParameters fields: |
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| 103 | |||
| 104 | * Name (required) |
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| 105 | * FaceId (required) |
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| 106 | |||
| 107 | FaceId is the FaceId returned in [[FaceMgmt|Face Management]]. |
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| 108 | If FaceId is omitted or is set to zero, it is implied as the requesting face (self deregistration). |
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| 109 | |||
| 110 | Self deregistration is unnecessary if client is quitting. NFD automatically removes routes belonging to a failed face. |
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| 111 | Client needs self deregistration when it stops serving a name prefix, but intends to continue execution. |
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| 112 | |||
| 113 | If face or route does not exist, this command does nothing, but is still considered successful. |
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| 114 | |||
| 115 | If the command succeeds, \<Body> in ControlResponse block contains updated ControlParameters: |
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| 116 | |||
| 117 | * Name: unchanged |
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| 118 | * FaceId: unchanged if request specifies non-zero; requesting FaceId if request omits or specifies zero |
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| 119 | |||
| 120 | ### Advertise a prefix |
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| 121 | |||
| 122 | **command-verb**: `advertise` |
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| 123 | |||
| 124 | ### Withdraw a prefix |
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| 125 | |||
| 126 | **command-verb**: `withdraw` |