| 1 | = Specifications = |
| 2 | |
| 3 | The following sections detail the specifications for a prototype MobilityFirst Network, and includes details of overall architecture, network elements, software services, protocols, end-host stack and network API. |
| 4 | |
| 5 | |
| 6 | == Name Resolution Service == |
| 7 | |
| 8 | |
| 9 | {{{ |
| 10 | LNRS servers GNRS servers |
| 11 | ^ ^ |
| 12 | | | |
| 13 | | | |
| 14 | +-----------------+ +-----------------+ |
| 15 | +---------------+ request +-----------------+ | | | | |
| 16 | | | ---------> | Local Agent | ----------> | Local Name | -----------> | Global Name | |
| 17 | | Host/Client | | Or | | Resolution | | Resolution | |
| 18 | | | <--------- | Default Gateway | <---------- | Service(LNRS) | <----------- | Service(GNRS) | |
| 19 | +---------------+ response +-----------------+ | server | | server | |
| 20 | +-----------------+ +-----------------+ |
| 21 | | | |
| 22 | | | |
| 23 | v v |
| 24 | LNRS servers GNRS servers |
| 25 | }}} |
| 26 | |
| 27 | === Host - GNRS interaction === |
| 28 | |
| 29 | A host may interact with the name resolution service to either (1) report/update it's present network location binding(s), or, (2) to query corresponding bindings of other network entities. The target of such a query operation may constitute either a host, a service, content or even a named context. Similarly, an update is not limited to the host's location, but of any addressable entity so long as it is authorized to do so. |
| 30 | |
| 31 | As illustrated above, an request message to the GNRS may be sent either to a local NRS agent, or to the default gateway if an agent isn't configured or hasn't been established at time of request. The address of such a local agent could be a static system configuration as in a '/etc' file on Unix systems, or established by a periodic broadcast from the agent itself. |
| 32 | |
| 33 | ==== Request Messages ==== |
| 34 | |
| 35 | |
| 36 | The following is the header of a name resolution request message: |
| 37 | |
| 38 | |
| 39 | {{{ |
| 40 | |
| 41 | 0 1 2 3 |
| 42 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| 43 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 44 | | Version |Type of Message| Total Length (L) | |
| 45 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 46 | | Request ID | |
| 47 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 48 | ~ ~ |
| 49 | | Sender Address N-bytes | |
| 50 | ~ ~ |
| 51 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 52 | ~ ~ |
| 53 | | Request Payload | |
| 54 | ~ ~ |
| 55 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 56 | }}} |
| 57 | |
| 58 | * Update Request Message |
| 59 | |
| 60 | An update involves reporting new network location bindings to the name resolution service. |
| 61 | |
| 62 | {{{ |
| 63 | 0 1 2 3 |
| 64 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| 65 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 66 | ~ ~ |
| 67 | | GUID N-bytes | |
| 68 | ~ ~ |
| 69 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 70 | | Options | |
| 71 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 72 | | Size (S) | |
| 73 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ -----+ |
| 74 | | | | | |
| 75 | | Type of Binding | Length of Binding (LB) | | |
| 76 | | | | | |
| 77 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |---- Entry for Binding #1 |
| 78 | ~ ~ | |
| 79 | | Network Location Binding | | |
| 80 | ~ ~ | |
| 81 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ -----+ |
| 82 | ~ ~ |
| 83 | | Bindings #2-#S | |
| 84 | ~ ~ |
| 85 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 86 | }}} |
| 87 | |
| 88 | * Lookup Request Message |
| 89 | |
| 90 | A lookup is performed to determine the present network location binding(s) of a network entity. |
| 91 | |
| 92 | {{{ |
| 93 | 0 1 2 3 |
| 94 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| 95 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 96 | ~ ~ |
| 97 | | GUID N-bytes | |
| 98 | ~ ~ |
| 99 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 100 | | Options | |
| 101 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 102 | }}} |
| 103 | |
| 104 | |
| 105 | ==== Early-binding ==== |
| 106 | |
| 107 | * It is assumed that an end-host has obtained the GUID(s) of the other communication end-point or network entity through an out-of-band mechanism. |
| 108 | * A host can initiate communication through one of the following API: |
| 109 | * sendTo(GUID, message, [serviceId], [serviceOptios], ...) |
| 110 | * get(GUID, ...) |
| 111 | * .... |
| 112 | * Implementations of the above API within the end-host's MF stack execute early-binding when requested |
| 113 | * A GNRS lookup message (GL-msg) is prepared for the dest-GUID. See section on GNRS message specification for included fields. |
| 114 | * Target NRS server: A default or preferred server may be specified in a local config file, or one obtained by listening to local advertisements |
| 115 | * GL-msg is sent out on the default interface for GNRS lookups |
| 116 | * Closest or preferred NRS server will execute the actual lookup on the GNRS service plane |
| 117 | * A GNRS lookup response (GLR-msg) prepared by server with mapping is routed to the querying entity, and is picked up by the stack |
| 118 | * End-host stack inserts the network address from GLR-msg into the message header and transmits the packet on appropriate interface |
| 119 | |
| 120 | |
| 121 | |