This chapter describes the StarOS VPC-SI architecture and interaction with external devices.
VPC-SI consolidates the operations of physical Cisco ASR 5500 chassis running StarOS into a single Virtual Machine (VM) able to run on commercial off-the-shelf (COTS) servers. Each VPC-SI VM operates as an independent StarOS instance, incorporating the management and session processing capabilities of a physical chassis.
Virtualized Mobility Functions
- Mobile Packet Core
- LTE MME (Mobile Management Entity), P-GW (PDN Gateway) and S-GW (Serving Gateway)
- GGSN Gateway GPRS Support Node
- SAE-GW System Architecture Evolution Gateway
- SGSN Serving GPRS Support Node (3G only)
- Mobile Control Plane PCRF (Policy and Charging Rule Function), application gateway, analytics, services orchestration, abstraction and control functions
- Small cell gateways
- HNBGW Home NodeB Gateway
- HeNBGW evolved Home NodeB Gateway
- SAMOG S2a Mobility over GTP combine CGW (Converged Access Gateway) and Trusted WLAN AAA Proxy (TWAP) functions on a single service node
Mobile Cloud Network (MCN) is a network infrastructure that includes Infrastructure as a Service (IaaS), the orchestration mechanisms, analytics mechanisms etc., upon which the VPC-SI as well as other services are deployed.
VM Interconnect Architecture
This figure below shows basic L2/L3 interconnection as supported by VPC-SI.
In the figure above, a virtual switch is embedded within the hypervisor to support SDN L2 capabilities across the data center. The virtual switch is interconnected to other virtual switches using 802.1Q trunks (VLANs). Typically, the virtual switch is a dynamically loaded kernel module.
VPC-SI is essentially StarOS running within a Virtual Machine (VM) on a COTS platform. It can be used as a stand-alone single VM within an enterprise, remote site, or customer data center. Alternatively, VPC-SI can be integrated as a part of a larger service provider orchestration solution.
The Single Instance architecture is best suited for low capacity scenarios. Scaling the VPC-SI Virtual Network Function (VNF) requires significant network level configurations for certain VNF types (such as, P-GW, S-GW, MME, PCRF, Firewall and NAT). For example, if a new VPC-SI P-GW is added or removed, various Diameter peers must be configured with this information DNS is provisioned or de-provisioned with this information.
VPC-SI only interacts with supported hypervisors KVM (Kernel-based Virtual Machine) and VMware ESXi. It has little or no knowledge of physical devices.
Typically, VPC-SI should be deployed in Interchassis Session Recovery (ICSR) pairs to provide physical redundancy in case of hardware or hypervisor failure.
Each VPC-SI VM takes on the roles of an entire StarOS system. The only interfaces exposed outside the VM are those for external management and service traffic. Each VM is managed independently.
Each VPC-SI VM performs the following StarOS functions:
- Controller tasks
- Out-of-band management for CLI and Logging (vSerial and vKVM)
- Local context vpnmgr
- Local context management (vNICs)
- System boot image and configuration storage on vHDD
- Record storage on vHDD
- NPU simulation via fastpath and slowpath
- Non-local context (vNICs, 1 to 12).
- Demux and vpnmgr for session processing
- Crypto processing