Page 272 - Cloud computing: From paradigm to operation

1 Framework and requirements for cloud computing

3) Inter-datacentre network: The network interconnecting remote cloud infrastructures. These
infrastructures may be owned by the same or different CSPs; an inter-datacentre network primarily
supports the following two scenarios:
– Workload migration, which means moving workloads from an enterprise datacentre to a CSP
datacentre, or moving workloads from CSP to CSP (for resilience and maintenance).
– Server clustering which allows transactions and storage replication for the business continuity.
Examples of inter-datacentre network models include:
1) private cloud datacentre to private cloud datacentre

2) private cloud datacentre to CSP datacentre
3) CSP datacentre to CSP datacentre.
NOTE 1 – For a description of a private cloud, please refer to [ITU-T Y.3500].
A centralized resource abstraction and control ensures the overall management of the cloud environment
with:
a) Network management systems that are dedicated to network service providers. The processes
supported by network management systems include management and maintenance of the network
inventory and the configuration of network components, as well as fault management.

b) Cloud management systems are dedicated to CSPs. Cloud management systems support processes
for maintenance, monitoring and configuration of cloud infrastructure resources.
NOTE 2 – Requirements for resource abstraction and control are provided in clause 10.

8.1 General requirements for networking resources

General requirements provided in this clause apply to networking resources of the access and core transport
networks, intra-datacentre networks as well as inter-datacentre networks.

The general requirements for networking resources include:
• Networking resources (e.g., bandwidth, number of ports, network addresses) are required to be
scalable;
• Networking resources are required to ensure services' performance and availability in order to meet
SLA objectives;
• Networking resources are required to be able to adapt dynamically to the traffic generated by cloud
services;

• Networking resources are required to support IPv4 and IPv6;
• Networking resources are recommended to support policy based control on flow by flow basis in a
fine-grained manner.

8.2 Access and core transport network
The access and core transport network is used to connect the CSC to the CSP for the use of cloud services.

The access and core transport network requirement includes:
• It is recommended that the access and core transport network supports the delivery of cloud
services in an optimal way in terms of performance, scalability and agility (e.g., through network
programmability).

8.3 Intra-datacentre network

The intra-datacentre network is used to connect local datacentre cloud infrastructures, such as servers,
storage arrays and L4-L7 devices (e.g., firewalls, load balancers, application acceleration devices).

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