Connect. Secure. Manage.
WAN Packet Loss Investigation
Trace packet loss across Cisco or Meraki WAN connections using correlated measurements, interface evidence and provider escalation where required.
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.
WAN packet loss investigation determines whether traffic is being discarded, where the evidence places the loss and how it affects the application. The distinction matters: an unanswered diagnostic probe is not always a lost business packet. MCI Network Services investigates Cisco and Meraki WAN paths using correlated observations, interface counters and application evidence. We aim to identify a defensible cause and a practical corrective action rather than recommend repeated restarts.
The whole path
Understand how sites, providers, cloud networks and security controls fit together.
Resilience that can be tested
Separate a second circuit from genuine end-to-end service resilience.
Provider coordination
Keep addressing, routing and escalation ownership clear across organisations.
Establish what is missing and where it was observed
We begin with the affected traffic, source, destination and time window. An application may report missing sequence numbers, TCP retransmissions or a timed-out transaction. Those signals do not all describe the same mechanism. We identify whether the evidence relates to packet delivery, application messages or recovery after an earlier failure, and preserve the terminology used by the application owner.
The observation point is recorded carefully. A capture on a receiving server shows what reached that interface, subject to capture reliability; it does not establish what left the source. A capture taken after address translation may not use the original source addresses. We map those transformations before filtering evidence so that relevant traffic is not excluded by an incorrect assumption about its identifiers.
Standards & partnerships
Confidence in the team behind your network.
Cisco Partner
Cisco Meraki
Cyber Essentials
Cyber Essentials PlusMCI Network Services is operated by Proxar Ltd. Certifications apply to the certified legal entity and the scope of its certificates. View accreditation information
Check local interfaces and capacity constraints
Physical errors, discards and queue drops provide different clues. We examine the counters supported by the actual Cisco or Meraki platform and compare their changes over the incident interval. Optical problems, cabling faults and speed mismatches can require a different response from congestion or provider policing. The report does not combine all counters under one generic loss figure.
Sampling intervals matter. Short bursts can fill a queue even when average circuit utilisation looks comfortable. We review the relationship between interface capacity, shaping, tunnel overhead and the provider’s service rate. A local queue that remains clear does not rule out a downstream drop point. Evidence from both sides of a handoff is valuable when establishing responsibility.
A useful starting point
Not sure where to start?
Bring the requirement. We will help you define the engineering work.
Use captures and probes with clear limitations
Where packet capture is authorised, we select the smallest useful scope and protect any sensitive data. We check capture drops and timestamp quality before treating missing packets in a file as proof of network loss. Comparing captures at separate points requires suitable clocks and an understanding of any duplication, fragmentation or encapsulation between them.
Active tests are chosen to resemble the relevant path and traffic class where practical. ICMP, UDP and application traffic may receive different treatment. A router’s control plane may rate-limit replies while forwarding customer traffic normally. We compare multiple sources of evidence and avoid declaring a particular hop faulty solely because it does not answer every probe.
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 ↗Examine routing, security and path changes
Packet loss can coincide with failover, tunnel changes, route convergence or a stateful security boundary. We correlate the incident with Cisco routing events, Meraki uplink history and firewall observations. Asymmetric paths, changed public addresses and fragmented traffic can produce symptoms that are not explained by circuit congestion alone.
We also distinguish sustained loss from a short transition followed by a longer application recovery. A feed handler, database client or remote session may take time to resynchronise after the network has recovered. Separating those intervals gives the customer a more accurate account of service impact and prevents an application recovery timer from being mistaken for carrier downtime.
Coordinate provider escalation with reproducible evidence
A useful escalation identifies the circuit, traffic direction, affected endpoints, timestamps and tests already completed. We include relevant counter changes and explain the limits of the available evidence. This gives the carrier or partner a specific segment to investigate rather than a request to check everything. Supplier records are compared with the customer-side timeline when they become available.
We do not promise to locate every lost packet inside infrastructure the customer cannot observe. Where the evidence narrows the fault to a provider path but not an individual device, that is the conclusion reported. Additional instrumentation or a jointly agreed test may be needed. The distinction between a proven boundary and an inferred internal cause remains explicit throughout the investigation.
Verify the remedy and improve future visibility
Corrective work may involve cabling, optics, capacity, shaping, routing or security policy. We define a post-change observation period and representative tests before declaring the issue resolved. A quiet period without sufficient traffic is weaker evidence than a repeat of the conditions that previously produced loss. Any remaining risk is recorded with an owner and review action.
MCI’s Cisco and Meraki network services can combine investigation with WAN outage analysis and monitoring improvements. For an initial assessment, provide the symptom, approximate timing and available captures or counters through an agreed secure method. We will identify what can be concluded from those records and what further evidence is necessary before changes are made.
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.
Existing customers should use their agreed support and escalation channels. This form is for service enquiries, not a monitored emergency ticket.
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