9 The term refers to making a copy of the system persistent data to a storage,
10 so that it can be used to restore the system or a given part of it to the same
11 state as it was when the backup was created. Restoring from backup will lose
12 volatile states like CPU and memory content. Changes made to the system from
13 the moment the backup was created to the moment it is used to restore the
14 (sub)system are also lost in the restoration process.
17 The refers to a system, or a hardware or software component that is extremely
18 reliable, well tested and proven in its capabilities. Carrier grade systems are
19 tested and engineered to meet or exceed "five nines" high availability standards,
20 and provide very fast fault recovery through redundancy (normally less than 50
21 milliseconds). Sometimes, Carrier grade is also referred as Carrier Class.
24 The term refers to an upgrade operation in which an earlier version of the
25 software is restored through the upgrade procedure. Compared to rollback,
26 Downgrade is normally initiated with Operator, and it is allowed to select any
27 earlier version, providing the compatibility of the versions is met or upgrade
28 strategies are allowed (whether service outage or data lost can be tolerant.)
31 The term refers to a subscriber of the Operator's services.
34 High Availability refers to a system or component that is continuously
35 operational for a desirably long length of time even a part of it is out of
36 service. Carrier Grade Availability is a typical HA example. HA system is popular
37 in Operator's data center for critical tasks. Non-HA system is normally deployed
38 for experimental or in-critical tasks in favor of its simplicity.
40 Infrastructure Services
41 The term refers to services provided by the NFV Infrastructure to the VNFs
42 as required by the Management & Orchestration functions and especially the VIM.
43 I.e. these are the virtual resources as perceived by the VNFs.
45 Infrastructure Resource Model
46 The term refers to the representation of infrastructure resources,
47 namely: the physical resources, the virtualization
48 facility resources and the virtual resources.
51 The term refers to a service provided by an Operator to its
52 end-users using a set of (virtualized) Network Functions
55 The term refers to network service providers and Virtual Network
56 Function (VNF) providers.
59 The terms refers to the period of time when a given service is not available
62 Parallel Universe Upgrade
63 The term refers to an upgrade strategy, which creates and deploys
64 a new universe - a system with the new configuration - while the old
65 system continues running. The state of the old system is transferred
66 to the new system after sufficient testing of the new system.
69 The term refers to a piece of hardware in the NFV infrastructure that may
70 also include firmware enabling this piece of hardware.
73 The term refers to a failure handling strategy that reverts the changes
74 done, for example, by an upgrade by restoring the system from some backup
75 data. This results in the loss of any change and data persisted after the
76 backup was been taken. To recover those additional measures need to be taken
77 if necessary (e.g. Rollforward).
80 The term refers to a failure handling strategy that reverts the changes
81 done by a potentially failed upgrade execution one by one in a reverse order.
82 I.e. it is like undoing the changes done by the upgrade.
85 The term refers to a failure handling strategy applied after a restore
86 (from a backup) operation to recover any loss of data persisted between
87 the time the backup has been taken and the moment it is restored. Rollforward
88 requires that data that needs to survive the restore operation is logged at
89 a location not impacted by the restore so that it can be re-applied to the
90 system after its restoration from the backup.
93 The term refers to an upgrade strategy, which upgrades a node or a subset
94 of nodes at a time in a wave style rolling through the data centre. It
95 is a popular upgrade strategy to maintain service availability.
98 The term refers to an upgrade that results in no service outage
102 The term refer to the state of a system at a particular point in time, or
103 the action of capturing such a state.
106 The term refers to a choreography that describes how the upgrade should
107 be performed in terms of its targets (i.e. upgrade objects), the
108 steps/actions required of upgrading each, and the coordination of these
109 steps so that service availability can be maintained. It is an input to an
110 upgrade tool (Escalator) to carry out the upgrade.
113 The duration of an upgrade characterized by the time elapsed between its
114 initiation and its completion. E.g. from the moment the execution of an
115 upgrade campaign has started until it has been committed. Depending on
116 the upgrade strategy, the state of the configuration and the upgrade target
117 some parts of the system may be in a more vulnerable state with respect to
118 service availability.
120 Virtualization Facility
121 The term refers to a resource that enables the creation
122 of virtual environments on top of the physical resources, e.g.
123 hypervisor, OpenStack, etc.
126 The term refers to a resource, which is provided as services built on top
127 of the physical resources via the virtualization facilities; in particular,
128 virtual resources are the resources on which VNFs are deployed. Examples of
129 virtual resources are: VMs, virtual switches, virtual routers, virtual disks.
135 The term is an abbreviation for Network Function Virtualization
136 Infrastructure; sometimes it is also referred as data plane in this
137 document. The NFVI provides the virtual resources to the virtual
138 network functions under the control of the VIM.
141 The term is an abbreviation for Virtual Infrastructure Manager;
142 sometimes it is also referred as control plane in this document.
143 The VIM controls and manages the NFVI compute, network and storage
144 resources to provide the required virtual resources to the VNFs.