Network Function Virtualization : Details on Compute Domain

1. Network Function Virtualisation -
Compute Domain
Neelima Sharma

2. The content of this presentation is taken from the ETSI
NFV specifications and from various presentations
available on internet

3. What is covered…
 Compute Domain – Overview
 Compute Domain – Architecture
 Compute Domain – Functional Elements
 Compute Domain – Deployment Scenarios
 Compute Domain – External Interfaces
 Compute Domain – E2E Requirements
 Compute Domain – Functional Blocks
 Compute Domain – Interfaces within domain
 Compute Domain - Modularity

4. Compute Domain - Overview
 Compute Domain includes :
 Storage
 Network
 I/O interfaces

5. Compute Domain – High Level Architecture

6. Compute Domain – General Architecture and Associated
Interfaces
 In the above figure following interfaces are important:
 Interface 11 : Compute domain and management and
orchestration
 Interface 14 : Interconnecting to infrastructure network

7. Compute Domain – Reference Architecture Framework

8. Compute Domain - Interest
 Compute Domain related interfaces:
 VNF-NFVI : Reference point between NFVI and VNF
 VI-Ha : Reference point interfacing the virtualization layer to the
hardware resources
 Nf-Vi : Reference point used to assign virtualized resources in
response to resource allocation requests

9. Compute Domain – Functional Elements
 Compute Domain includes following functional elements :
 Processor and Accelator
 x86 or ARM based
 Network interfaces ( NIC’s) card
 Storage
Large scale and non-volatile like hard disks, solid state disks and so on.

10. Compute Domain – Deployment Scenarios

11. Compute Domain – External Interfaces
 Physical network Interfaces
 Ethernet
 CAT 5/ 6 cable with speed up to 1 Gbps
IEEE802.3 specs compliant
 Fibre-Channel
Fibre channel with speeds : 1, 2, 4, 8, 10, 16 and 20 Gbps
4G and 8G standard compliant
 Infniband
Serial style of interface
 QDR, FDR, EDR speeds

12. Compute Domain – External Interfaces
 Internal and External domain interfaces
 NFVI to VIM (Nf-Vi)
 Nf-Vi/C
 Used by VIM to manage the compute and storage portion of NFVI
 Vi-Ha/csr
 Interface between the compute domain and hypervisor domain
 Used by hypervisor/OS to monitor the available physical resources of the
compute domain
 Management and Orchestration interfaces

13. Compute Domain – E2E Requirements
 Below attachment defines the E2E requirement for compute and
storage

14. Compute Domain – Functional Blocks
 Definition
“An NFV compute node is a coherent domain with an instruction set
architecture that is managed as a single compute execution environment. A
compute node includes a NIC to communicate with other compute nodes,
network elements and storage elements”
Various blocks of the compute Domain are detailed below :
 CPU Complexity
 Level of integration
 H/W and S/W interfaces
 Hypervisor interfaces
 Instruction-sets and programmability
 Number of CPU sockets
 Clock speed and form factor

15. Compute Domain – Functional Blocks
 Network Interfaces and Accelerator
 NIC to include H/W acceleration engines for encryption, encapsulation,
forwarding and switching
 Hardware accelerators such as encryption, digital signal processing
(DSP), packet header processing, packet buffering and scheduling etc
support
 Additions to the instruction set architecture which implement new s/w
acceleration features

16. Compute Domain – Functional Blocks
 H/W abstraction layer implemented by the hypervisor and guest O.S

17. Compute Domain – Interfaces within domain
 PCIe
 Interconnects the NIC and/or acceleration cards to the host CPU
 SR-IOV ( Single Root I/O Virtualisation)
 Used to virtualize the PCIe and the attached NIC
 One physical NIC card can support up to 128 virtual functions (VF’s)
 Assigning each PCI express virtual function can be directly assigned to
a virtual machine
 I/O overhead in the software emulation layer is diminished

18. Compute Domain – Interfaces within domain
 RDMA ( Remote direct memory access)
 Allows server-to-server data movement directly between applications
memory
 Provides low latency, improved resource utilization, flexible resource
allocation, scalability and unified fabric
 RDMA over Converged Ethernet (RoCE)
 New RDMA protocol over Ethernet
 Provide data center convergence over reliable Ethernet and Data center
bridging (DCB)
 RoCE communications can be as low as 1/10th the latency of any other
standards

19. Compute Domain – Interfaces within domain
 Infiband
 Direct access to a Network Interface (NIC) straight from application
space
 Ability for apps to exchange data directly between their respect buffers
across a network
 Creation of a virtual channel connecting two applications which exist in
entirely separate address space
 Provides messaging service that application can access
 Used for storage, IPC, message exchanging
 Deliver higher bandwidth and low latency

20. Compute Domain – NFVI Modularity
 NFVI hardware resource modularity options

21. Compute Domain – NFVI Modularity
 Composite - NFVI
 NFVI from COTS elements like servers, disk, switches, power supplies,
fans and so on
 Another approach is use of an OCP pooled resource structure
 Field replaceable units are components of the NFVI
 NFVI-Pod
 NFVI from COTS elements but with no field replaceable units
 Deployed with various capacities and form factor
 Failed elements will be marked as unavailable for use
 NFVI-Plugin
 COTS deployable unit of NFVI H/W resources that is field replaceable
unit within some other network element
 Managed by the NFV management and orchestration entities

22. Compute Domain – NFVI Modularity
 Composite - NFVI
 NFVI from COTS elements like servers, disk, switches, power supplies,
fans and so on
 Another approach is use of an OCP pooled resource structure
 Field replaceable units are components of the NFVI
 NFVI-Pod
 NFVI from COTS elements but with no field replaceable units
 Deployed with various capacities and form factor
 Failed elements will be marked as unavailable for use
 NFVI-Plugin
 COTS deployable unit of NFVI H/W resources that is field replaceable
unit within some other network element
 Managed by the NFV management and orchestration entities