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Cisco Source-Specific Multicast
Assess and implement source-specific multicast on Cisco networks, checking receiver support, source addressing and the operational model.
Devices supported
across the UK
Client locations
supported
Traffic handled
at peak time
Average
response time
Average response is not a resolution time or a contractual guarantee. Support scope and response commitments are agreed for each engagement.
Cisco Source-Specific Multicast provides delivery for a receiver that requests a particular source and multicast group together. This source-and-group model can simplify distribution where applications know exactly which sender they need, but it depends on receiver support and correct source reachability. MCI Network Services assesses and implements source-specific multicast on supported Cisco networks, checking the complete application and forwarding path before treating it as an alternative to an existing multicast design.
Cisco-focused engineering
Design around the platform, traffic and failure behaviour you actually operate.
Change with evidence
Use pre-checks, acceptance criteria and a documented route back.
Operational handover
Keep the configuration, diagrams and responsibilities understandable after delivery.
Confirm that the application can identify its source
A source-specific service needs more than a group address in a configuration sheet. We establish how receivers learn the source address, how they express the subscription and whether the address can change during failover. The application owner or provider must confirm those details because the network cannot infer an intended source from an ambiguous request.
For IPv4, IGMPv3 source-aware membership is relevant to native source-specific operation. A compatible operating system alone does not prove that the application uses the necessary subscription method. We review the actual receiver behaviour, including virtualised hosts and appliances whose interfaces expose only limited multicast settings.
Standards & partnerships
Confidence in the team behind your network.
Cisco Partner
Cisco Meraki
Cyber Essentials
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Define the source-and-group register
We document each approved source, group, receiver population and transport service. The register should identify who owns the addressing and how changes are communicated. This is especially important for externally supplied feeds, where a source change can require coordination across network policy and application configuration.
The group range configured for source-specific treatment must match the agreed architecture. We avoid assuming that every existing multicast address can simply be reclassified without consequences. Other services may rely on any-source behaviour or a rendezvous point, and those dependencies need to remain intact during a staged deployment.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Check the routed path to the source
Source-specific multicast builds distribution toward the selected source, so the network needs an appropriate route and reverse-path expectation. We review source reachability, PIM configuration where required, routing contexts and any policies that influence the incoming interface. Ordinary connectivity tests provide only part of that evidence.
A dual-provider or multi-site design needs particular attention. The preferred unicast route may change independently of the packet arrival path used by a provider. We document how those relationships are intended to behave and test approved failure scenarios rather than adding static routes without understanding the underlying asymmetry.
Different environments. The same care.
Built around the work
your network supports.
Finance, banking and the wider private sector. We start with the systems and people that depend on your connections.
Finance & banking
Market-data paths, routing and provider coordination on clients’ behalf.
Financial-market services ↗Offices & multi-site teams
Reliable access between people, workplaces and business applications.
Office network design ↗Data centres & cloud
Network boundaries, workload connections and operational ownership.
Data centre networks ↗Handle legacy receivers explicitly
Some Cisco platforms offer mapping mechanisms that can associate a group-only request with a source. Such mechanisms may help with a specific legacy requirement, but they are not equivalent to an application natively selecting its source. We verify support and document where the mapping is maintained and who may change it.
A mapping also creates an operational dependency. If a source moves, the application may still appear correctly configured while the network continues requesting the old sender. We assess whether upgrading or reconfiguring the receiver would provide a clearer long-term solution instead of expanding an increasingly complicated set of exceptions.
Review boundaries and capacity
A source-specific subscription narrows the requested sender, but it does not replace access controls, provider entitlements or traffic boundaries. We define which sources and groups may enter the estate and which segments may receive them. Firewall and platform support must be checked along the complete path.
Capacity planning considers the number of source-and-group entries, replication points and stream rates. Two feeds sent to separate receivers can create different load from the same feeds replicated across many ports. We also examine the remaining capacity after a link or device failure, not just the normal operating state.
Prove subscription and delivery
Testing begins with the receiver’s actual membership request and follows the resulting forwarding state toward the source. We verify that the intended traffic arrives and that a different source using the same group is not mistaken for the required service. Captures and counters are interpreted with their location and limitations recorded.
The test plan includes starting and stopping receivers, source availability and any agreed redundancy behaviour. Application recovery remains a separate observation from network convergence. A packet stream may return promptly while a receiver requires replay, resynchronisation or another application-level action before useful service resumes.
Keep source changes controlled
The handover includes the source-and-group register, relevant configuration, mapping exceptions, tests and escalation contacts. New sources or address changes should pass through a documented process involving the provider or application owner. This avoids treating a deliberate source restriction as an unexplained network fault months later.
MCI can assess source-specific multicast readiness or implement it within a broader Cisco IP multicast service. We define which receivers are suitable, what network work is required and how the resulting delivery will be verified, without assuming that all existing multicast applications can use the same model.
Talk to a specialist
What does your network need next?
Tell us what you are planning, changing or trying to improve. We will help define a practical next step and the engineering scope.
+44 203 196 6566Choose option 1
sales@proxar.co.ukUK-wide service.
Most of our engineers are based in Kent, with a focus on London, Sussex, Essex and Berkshire.
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