RibMgmt » History » Version 3
Junxiao Shi, 04/18/2014 10:59 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 | 3 | Junxiao Shi | * origin |
| 20 | 1 | Junxiao Shi | * cost |
| 21 | * route inheritance flags |
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| 22 | |||
| 23 | 3 | Junxiao Shi | ### Route origin |
| 24 | |||
| 25 | **Origin** indicates who is announcing a route. |
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| 26 | |||
| 27 | * **app**(=0): local producer application |
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| 28 | * **static**(=255): static route |
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| 29 | * **nlsr**(=128): NLSR |
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| 30 | |||
| 31 | ### Route cost |
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| 32 | |||
| 33 | 1 | Junxiao Shi | **Cost** indicates the preference among multiple routes with same Name prefix. |
| 34 | 3 | Junxiao Shi | The nexthop face on a route with lower cost is preferred. |
| 35 | |||
| 36 | 1 | Junxiao Shi | Unlike IP routing, the nexthop face to use is decided by forwarding strategy. |
| 37 | 3 | Junxiao Shi | Route cost is a suggestion to strategy; strategy MAY consider route cost when making forwarding decisions. |
| 38 | 1 | Junxiao Shi | |
| 39 | ### Route inheritance |
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| 40 | |||
| 41 | Each route can have two route inheritance flags: |
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| 42 | |||
| 43 | * CHILD\_INHERIT: indicates that this route may be used even if a longer prefix is matched. |
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| 44 | This flag applies on a single route. |
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| 45 | * CAPTURE: indicates that no shorter prefix can be used; overrides CHILD\_INHERIT. |
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| 46 | 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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| 47 | |||
| 48 | Example: |
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| 49 | |||
| 50 | Name prefix | nexthop FaceId | CHILD\_INHERIT | CAPTURE |
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| 51 | ------------|----------------|----------------|--------- |
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| 52 | / | 1 | yes | no |
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| 53 | / | 2 | no | no |
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| 54 | /A | 3 | yes | no |
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| 55 | /A/B/C | 4 | yes | no |
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| 56 | /D | 5 | yes | yes |
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| 57 | /D | 6 | yes | no |
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| 58 | |||
| 59 | * Interest /A/P can go to face 1 and 3. |
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| 60 | * It cannot go to face 2, because that route has CHILD\_INHERIT=no. |
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| 61 | * Interest /A/B/C/Q can go to face 1, 3, and 4. |
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| 62 | * Interest /D/R can go to face 5 and 6. |
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| 63 | * It cannot go to face 1, because one of the routes on /D sets CAPTURE=yes. |
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| 64 | * Interest /S can go to face 1 and 2. |
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| 65 | |||
| 66 | ## Control Commands |
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| 67 | |||
| 68 | [[ControlCommand]] **management-module**: `rib` |
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| 69 | |||
| 70 | ### Register a route |
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| 71 | |||
| 72 | **command-verb**: `register` |
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| 73 | |||
| 74 | This command adds a route to the RIB. |
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| 75 | |||
| 76 | ControlParameters fields: |
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| 77 | |||
| 78 | * Name (required) |
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| 79 | * FaceId (optional) |
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| 80 | 3 | Junxiao Shi | * Origin (optional) |
| 81 | 1 | Junxiao Shi | * Cost (optional) |
| 82 | 3 | Junxiao Shi | * Flags (optional) |
| 83 | 1 | Junxiao Shi | * ExpirationPeriod (optional) |
| 84 | |||
| 85 | FaceId is the FaceId returned in [[FaceMgmt|Face Management]]. |
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| 86 | If FaceId is omitted or is set to zero, it is implied as the requesting face (self registration). |
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| 87 | If face does not exist, the command fails with code 410. |
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| 88 | |||
| 89 | 3 | Junxiao Shi | Origin defaults to app(=0). |
| 90 | |||
| 91 | Cost defaults to zero. |
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| 92 | |||
| 93 | 1 | Junxiao Shi | Flags is an inclusive OR of route inheritance flags. |
| 94 | CHILD\_INHERIT=1, CAPTURE=2. |
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| 95 | It defaults to CHILD\_INHERIT. |
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| 96 | |||
| 97 | 3 | Junxiao Shi | ExpirationPeriod gives the duration (in milliseconds) in which this route is effective. |
| 98 | After ExpirationPeriod has elapsed, or when the face fails, the route is removed. |
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| 99 | ExpirationPeriod defaults to (practically) Infinity when FaceId is omitted or is set to zero; otherwise, it defaults to 1 hour. |
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| 100 | 1 | Junxiao Shi | |
| 101 | 3 | Junxiao Shi | If a route of same Name, FaceId, and Origin exists, its Cost and Flags are updated, and its lifetime is extended to now + ExpirationPeriod. |
| 102 | 1 | Junxiao Shi | |
| 103 | 3 | Junxiao Shi | If the command succeeds, \<body> in ControlResponse block contains updated ControlParameters: |
| 104 | 1 | Junxiao Shi | |
| 105 | * Name: Name prefix |
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| 106 | * FaceId: nexthop FaceId |
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| 107 | 3 | Junxiao Shi | * Route: route origin |
| 108 | * Cost: route cost |
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| 109 | 1 | Junxiao Shi | * Flags: inclusive OR of route inheritance flags |
| 110 | * ExpirationPeriod: remaining lifetime (in milliseconds) |
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| 111 | |||
| 112 | ### Unregister a route |
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| 113 | |||
| 114 | **command-verb**: `unregister` |
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| 115 | |||
| 116 | This command removes a route from the RIB. |
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| 117 | |||
| 118 | ControlParameters fields: |
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| 119 | |||
| 120 | * Name (required) |
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| 121 | 3 | Junxiao Shi | * FaceId (optional) |
| 122 | * Origin (optional) |
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| 123 | 1 | Junxiao Shi | |
| 124 | FaceId is the FaceId returned in [[FaceMgmt|Face Management]]. |
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| 125 | If FaceId is omitted or is set to zero, it is implied as the requesting face (self deregistration). |
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| 126 | |||
| 127 | 3 | Junxiao Shi | Origin defaults to app(=0). |
| 128 | |||
| 129 | 1 | Junxiao Shi | Self deregistration is unnecessary if client is quitting. NFD automatically removes routes belonging to a failed face. |
| 130 | Client needs self deregistration when it stops serving a name prefix, but intends to continue execution. |
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| 131 | |||
| 132 | If face or route does not exist, this command does nothing, but is still considered successful. |
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| 133 | |||
| 134 | 3 | Junxiao Shi | If the command succeeds, \<body> in ControlResponse block contains updated ControlParameters: |
| 135 | 1 | Junxiao Shi | |
| 136 | * Name: unchanged |
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| 137 | * FaceId: unchanged if request specifies non-zero; requesting FaceId if request omits or specifies zero |
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| 138 | |||
| 139 | ### Advertise a prefix |
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| 140 | |||
| 141 | **command-verb**: `advertise` |
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| 142 | |||
| 143 | 3 | Junxiao Shi | This command is not defined in this revision. |
| 144 | |||
| 145 | 1 | Junxiao Shi | ### Withdraw a prefix |
| 146 | |||
| 147 | **command-verb**: `withdraw` |
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| 148 | 3 | Junxiao Shi | |
| 149 | This command is not defined in this revision. |