, page 1 Topology Overview, page 2 About the Cisco Application Policy Infrastructure Controller Enterprise Module (APIC-EM), page 5 The Cisco Wide Area Bonjour solution is based on a distributed and hierarchical Bonjour service learning and distribution architecture. This architecture consists of the following components: Cisco APIC-EM controller Wide Area Bonjour application (formerly known as SD-Bonjour) that is installed and enabled on the controller Next-generation Cisco Catalyst switches that support a Service Discovery Gateway (SDG) agent The Service Discovery Gateway (SDG) agent supports a two tier SDG functionality: local Area and wide area SDG. In local area SDG, the Cisco switches function between the Catalyst switch and end-point devices, whether wired or wireless. To discover Bonjour services beyond a single Layer 3 boundary, the SDG agent consults the new Cisco Wide Area Bonjour application (installed and enabled on the Cisco APIC-EM controller) and receives policy-based remote Bonjour service entries to distribute in the local network. The Multicast DNS (mdns) boundary remains limited to the SDG agent and is not extended over the IP network. The network communication between Wide Area Bonjour application and agent is simple TCP/IP based and does not extend any Multicast DNS (mdns) Layer 2 boundary over the enterprise core or WAN network. This two tier SDG design ensures both the network bandwidth and reliability. The Wide Area Bonjour application provides an end-to-end Enterprise-class Apple Bonjour solution in the network. The Cisco Wide Area Bonjour is a software-defined, policy-based Apple Bonjour protocol controller that facilitates both multicast and unicast DNS-based service discovery. Wide Area Bonjour is designed for the Cisco APIC-EM platform and enables service discovery across the enterprise network, while also relieving load off of devices within that network. Information about services learned from the access layer are unicast to the Cisco APIC-EM and stored within its database. The stored service data is also sent to other clients on different subnets across the network based upon user-configured filters. The Wide Area Bonjour application enables policy-based Bonjour discovery and distribution across the user-defined network. In this distributed and hierarchical architecture, the next-generation Cisco Catalyst switches provides Service Discovery Gateway (SDG) Agent function. The solution offers centralized policy-management and monitoring function with 1
Topology Overview highly scalable distributed architecture for large scale Bonjour deployments. This end-to-end solution is made possible between Cisco APIC-EM controller, next-generation Catalyst switching platforms, along with supporting features from Cisco WLC platforms. Related Topics Topology Overview, on page 2 About the Cisco Application Policy Infrastructure Controller Enterprise Module (APIC-EM), on page 5 Topology Overview The following figure displays a topology of how the Cisco Wide Area application enables Bonjour service discovery and distribution in the IP network. Figure 1: Wide Area Bonjour Topology The topology mainly consists of the following components: Bonjour Endpoints These are end user devices or end points which are capable of announcing Bonjour services into the network or discovering the services. Examples of services are printers, Apple TV, file transfer services such as SMB or AFP, Philips Hue light and so on. SDG Agent These are Cisco catalyst switches that contains policies and performs service discovery, service caching and service filtering functions. Cisco Wide Area Bonjour App This app function is paired with Cisco Catalyst switches in an agent role to enable centralized Bonjour service caching service providing policy-based service distributed to Cisco Catalyst Switches (SDG Agent). The Cisco Wide Area Bonjour app is supported on the Cisco APIC-EM physical appliance. The Wide Area topology consists of two layers Local Area SDG and Wide Area SDG. Local Area SDG: Individual catalyst switches can act as local area SDG. In this role,it acts as local Bonjour proxy function between VLANs. The Bonjour endpoints can be on LANs or WLANs. 2
Wide Area Bonjour Workflow Wide Area SDG: The Wide Area Bonjour App running on APIC-EM acts as the Wide Area service discovery gateway. It provides proxy functionality among the local area SDGs. Related Topics, on page 1 Wide Area Bonjour Workflow The following figure shows the overall workflow and the policies that are applied across network, SDG agents and controllers. Figure 2: Wide Area Bonjour Workflow and Policies Referring to the above figure, the following table lists the policies and its description: Table 1: List of Policies and Description 1 2 Policy Local Area SDG Agent Filters Wide Area SDG Agent Filters Description Enforced on SDG Agent in Layer 2 Network Domain. IP traffic flow between the local area SDG agent filters is bi-directional. Enforced on SDG Agent for export control to controller. IP traffic flow between the wide area SDG agent filter and the IP network is uni-directional. 3
Wide Area Bonjour Workflow 3 Policy Wide Area Bonjour Application Policy Description Enforced on Controller for global discovery and distribution. IP traffic flow between the Wide Area Bonjour Application and the IP network is bi-directional. The Cisco Wide Area Bonjour solution follows a client/server model. The SDG agent functions as a client and the Cisco Wide Area Bonjour application functions as a server. Referring to the Figure 2: Wide Area Bonjour Workflow and Policies, the below sections describe the workflow of service announcement and discovery in the IP network. Announcing Services into the Network 1 The end-point devices (Source) in local area SDG send service announcements to SDG agent and specifies the network what services they are capable of (For example:_airplay._tcp.local, raop._tcp.local and so on). 2 The SDG agent listens to these announcements and matches them against the policies (Local Area SDG Agent Policy) that were configured. In this case, either of the following scenarios occur: If the announcement matches the policy, SDG agent will cache it and advertise them to Wide Area Bonjour App through Bonjour Control Protocol based on the configured Wide Area SDG Agent Policy. If the announcement does not matches the policy, it will drop it. 3 Based on the policies on the Wide Area Controller Policy, the controller stores all these matched service announcements in its centralized Bonjour cache. Discovering Services Available in the Network 1 The endpoint device (receiver) connected to the local area SDG agent sends a Bonjour query to discover the services available using mdns protocol. 2 SDG agent listens to these queries and matches them against the Local Area SDG agent filters that are configured. Either of the following scenarios occur: If the query matches one of the filters: Matching services from the SDG agent's cache are immediately responded. This same query is replicated to Wide Area Bonjour App, if the Wide Area SDG agent filter allows it, over the IP network using Cisco Bonjour Control Protocol. If the query does not match any of the filters, it will be dropped. 3 Upon receiving the query from SDG agent, Wide Area Bonjour App matches the configured policies in the app. If the query is matched, it responds with the corresponding services from its cache to SDG agent using Cisco Bonjour Control Protocol. 4 Upon receiving responses from the Wide Area Bonjour App, SDG agent forwards them to the corresponding end points using mdns. 4
About the Cisco Application Policy Infrastructure Controller Enterprise Module (APIC-EM) About the Cisco Application Policy Infrastructure Controller Enterprise Module (APIC-EM) The Cisco Application Policy Infrastructure Controller - Enterprise Module (APIC-EM) is Cisco's Software Defined Networking (SDN) Controller for Enterprise Networks (Access, Campus, WAN and Wireless). The platform hosts multiple applications (SDN apps) that use open northbound REST APIs that drive core network automation solutions. The platform also supports a number of south-bound protocols that enable it to communicate with the breadth of network devices that customers already have in place, and extend SDN benefits to both greenfield and brownfield environments. The Cisco APIC-EM platform supports both wired and wireless enterprise networks across the Campus, Branch and WAN infrastructures. It offers the following benefits: Creates an intelligent, open, programmable network with open APIs Saves time, resources, and costs through advanced automation Transforms business intent policies into a dynamic network configuration Provides a single point for network wide automation and control Related Topics, on page 1 5
About the Cisco Application Policy Infrastructure Controller Enterprise Module (APIC-EM) 6