Page 60 - Kaleidoscope Academic Conference Proceedings 2022

2022 ITU Kaleidoscope Academic Conference

2) Computing service gateway: In the overlay service In this paper, the IP prefix part of the anycast IP of the
anycast system, the computing service gateway is used as the computing service instance will be globally reserved to
gateway of the computing service instance, driven by the prevent it from being assigned to other unicast interfaces.
SRv6 protocol, and communicates with the access gateway The interface ID part of the anycast IP address of the
through a unicast address. Its role is similar to the proxy of computing service instance will be determined by the unique
computing service instances and the operator of the ID of the computing service provided by the computing
computing service instances will configure multiple SIDs for service instance, which can be managed and generated
the computing service gateway. The SID is a special IPv6 through a certain computing service registration mechanism.
address used in the SRv6 protocol to identify a forwarding
action or function on a routing node device. On the The SID of the computing service gateway corresponds to a
computing service gateway, each SID corresponds to a computing service instance behind the computing service
computing service instance deployed behind the computing gateway in this paper, so in order to help the control plane
gateway. When a packet with a destination address of a discover the computing service and make policy decisions,
certain SID is received, the computing service gateway will the unique ID of the computing service is added to the SID
strip the SRH and forward the inner data packet to the back- in the function field, while the locator field remains allocated
end computing service instance. In actual deployment, it can by the network. In this way, the control plane can discover
be the Point of Presence (POP) device of the cloud data the back-end ready service instances through the SIDs
center and the gateway device of the edge computing node, enabled on the computing service gateway in order to
and the computing service gateway can also have the manage and configure SRv6 policies.
function of an access gateway.

3) Control plane: In the overlay service anycast system, the
control plane can dynamically discover the configured SID
on the computing service gateway and provide SRv6 policies
and corresponding SRHs for the access gateway. The control
plane can also monitor the network quality and status
between each access gateway and computing service
gateway in real time and obtain the status information of each
computing service instance through the interface with each
computing infrastructure controller. The control plane also
maintains the computing and network KPI requirements of
each computing service. Therefore, each access gateway can
be configured with an SRv6 policy that leads to one or a
group of computing service gateways that meet the
requirements through the control plane, so as to access the
computing service under the premise of ensuring the service Figure 2 – IP address identification design
quality of experience.
4.5 Load balancing strategy
4) Computing service instance: In the overlay service
anycast system, the computing service instance acts as the Once the control plane obtains the computing services
server of each computing service. All computing instances supported by each computing service gateway, it can make
that provide the same computing service share the same load balancing decisions by configuring the SRv6 policies
anycast IP address globally, so there is one and only one for the access gateway. Unlike other traditional load
computing service instance behind a computing service balancing solutions, the control plane, as a part of the
gateway. When multiple computing service instances have network infrastructure, is able to know the connection status
to be deployed behind the same computing service gateway, and quality between each access gateway and computing
the anycast IP address should be shared through other local service gateway, which provides the possibility for QoE
L3 load balancers. optimization. Since the control plane itself does not maintain
the status information of each computing service instance,
4.4 Service resource discovery based on IP address this information must be obtained from the computing
identification infrastructure controller. Typical computing service instance
status information may include load information and
The IPv6 protocol provides a vast address space, which performance information.
makes it possible to carry more information in IP addresses.
By using the computing service identification information In addition, in order to reduce the number of SRv6 policies
carried in the IP address, it can help the control plane to make active on the access gateway, the control plane should also
decisions on the routing paths of specific users and specific obtain the service area restrictions of each computing service
computing services, as in Figure 2. instance and network KPI requirements of each computing
service instance. The SRv6 policies corresponding to the
service instance that do not meet the service area restrictions

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