70-333 Exam Guide: Deploying Enterprise Voice with Skype for Business 2015
Exam 70-333, identified by Microsoft as “Deploying Enterprise Voice with Skype for Business 2015,” validates practical knowledge of planning, securing, deploying, configuring, and administering Enterprise Voice in Skype for Business Server. It was intended for professionals responsible for voice infrastructure rather than candidates studying general collaboration features. The immediate decision is whether this legacy exam remains a viable certification objective for you, or whether its technical content should be used as a skills study plan instead.
Should you still plan to take 70-333?
Treat 70-333 as a legacy exam objective and verify availability directly with Microsoft before spending time on scheduling. Microsoft listed 70-333 among exams associated with retiring MCSA, MCSD, and MCSE paths. The retirement announcement contains an initial June 30, 2020 date and a later update stating January 31, 2021 for remaining exams, so the official source should control any current decision.
The announcement says that, once the relevant exams retired, candidates could no longer earn the associated certifications through those exams. It also says existing MCSA, MCSD, and MCSE certifications remain on a Microsoft transcript, with the certification moving to the inactive section after the stated active period. That distinction matters: preserving an existing credential is different from starting a new certification attempt.
Before building a booking plan, check Microsoft’s current certification and exam information rather than relying on an archive, a reseller listing, or a practice-test page. If 70-333 is unavailable, use the official Skype for Business Server documentation as a technical learning source and investigate a current role-based certification that matches your present work. Microsoft’s retirement announcement specifically describes role-based certifications as the continuing direction.
What capability does the exam represent?
The subject is Enterprise Voice implementation in Skype for Business Server 2015: turning a communications topology into a working voice service connected to the public switched telephone network. The official documentation places the work across planning, deployment, configuration, management, and Enterprise Voice, so preparation should follow an end-to-end implementation sequence rather than isolated command memorization.
A candidate should be able to reason about sites and regions, branch connectivity, PSTN connectivity, Mediation Servers, gateways or SIP trunks, Edge services, normalization, dial plans, voice policies, routes, user enablement, and advanced call features. These are the practical skill areas evidenced by Microsoft’s planning, component, deployment, and user-enablement documentation; they are not a reproduced official percentage blueprint.
The technology context is broader than voice alone. Microsoft describes Skype for Business Server 2015 documentation as covering instant messaging, presence, conferencing, video, and telephony solutions. For this exam, however, use those wider capabilities as context for voice integration and troubleshooting, not as permission to give equal study time to every server feature.
Which architecture decisions deserve priority?
Start with the call path and topology. A typical reasoning chain is user endpoint, Skype for Business Front End components, Mediation Server, PSTN gateway or SIP trunk, and the external telephone network. Mediation Servers translate signaling and, in some configurations, media between Skype for Business Server, Enterprise Voice infrastructure, and PSTN connectivity. Knowing that role helps you predict where a signaling, media, or interoperability problem belongs.
Microsoft identifies Mediation Servers, PSTN connectivity components, and Edge Servers as Enterprise Voice components. Mediation Servers may be collocated with Front End Servers or installed as standalone servers. Edge services support users outside the organization’s firewall: Access Edge handles SIP signaling, while A/V Edge supports media traversal of network address translation and firewalls.
Build a component map before studying configuration commands. For each component, record its purpose, placement options, dependency, and likely failure symptom. Then ask whether a scenario requires local PSTN access, external-user media traversal, a standalone Mediation Server pool, or a collocated deployment. This method is more useful than memorizing a list because it forces you to connect design choice to operational consequence.
How should you approach Enterprise Voice planning?
Planning begins with sites, regions, network links, call volume, redundancy, failover, and any existing PBX equipment. Microsoft also directs planners to decide where gateways, Survivable Branch Appliances, and SIP trunks should be deployed. Record these decisions in a site matrix before looking at deployment procedures; otherwise, you may study configuration steps without understanding the topology they implement.
For branch sites with resilient WAN links, Microsoft recommends considering a gateway at each branch for local direct inward dial termination. If bandwidth is constrained, call admission control may be appropriate. For a branch without resilient WAN links, the guidance distinguishes between a Survivable Branch Appliance for a smaller site without local trained administrators and a Survivable Branch Server with a small gateway for a larger stated user range when trained administrators are available.
Do not turn these recommendations into universal design rules. They depend on the conditions named by Microsoft, including WAN resilience, branch population, and administrator availability. In your notes, write the condition first and the recommended component second. That habit prepares you for scenario questions in which several options appear technically possible but only one fits the stated constraints.
How do you estimate PSTN capacity?
Use the traffic model only after identifying the site and expected calling pattern. Microsoft’s planning guidance gives Light traffic as one PSTN call per user per hour and uses 15 users per port, Medium traffic as 2 PSTN calls per user per hour and uses 10 users per port, and Heavy traffic as 3 or more PSTN calls per user per hour and uses 5 users per port.
Keep the domain label attached to every figure in your study notes: Light traffic—15 users per port; Medium traffic—10 users per port; Heavy traffic—5 users per port. Do not compare the numbers as generic capacity ratios. They describe a planning metric for estimating site traffic and the number of ports required, not a guaranteed production design.
A practical exercise is to take a fictional site, classify its traffic as Light, Medium, or Heavy using the documented definitions, and calculate the resulting port estimate. Then list what the simple calculation does not decide: gateway placement, redundancy, WAN behavior, carrier requirements, and failover. This separates arithmetic from architecture and prevents a capacity estimate from being mistaken for a complete voice design.
What security and administrative prerequisites must you know?
Enterprise Voice deployment depends on both infrastructure security and correctly scoped administrative rights. Microsoft states that deployment administrators should belong to RTCUniversalServerAdmins, while voice configuration and user-management tasks can be assigned through Skype for Business administrative roles. A managed key infrastructure using a Microsoft or third-party certification authority is also required.
Learn the difference between CsVoiceAdministrator, CsUserAdministrator, and CsAdministrator. CsVoiceAdministrator can perform voice configuration tasks, manage voice applications, and assign voice policies. CsUserAdministrator can manage user properties such as Enterprise Voice enablement and assign per-user policies, with the documented exceptions. CsAdministrator combines the tasks of the two roles.
For each administrative scenario, ask two questions: is the task topology or voice configuration, and is it a user-property change? Then select the narrowest documented role that can perform it. Also include certificates in your prerequisite checklist, but consult the linked environmental or server requirements for detailed certificate rules rather than inventing a certificate design from memory.
What is the correct deployment sequence?
Study deployment as a dependency chain: verify prerequisites, define or publish the topology, install or confirm Mediation Server components, define PSTN gateways and trunks, create translation and normalization rules, configure dial plans and voice policies, create PSTN usage records and voice routes, enable users, and then add advanced voice or call-management features.
Microsoft’s central-site deployment guidance explicitly covers Mediation Server deployment, gateway and trunk definition, caller ID and called ID translation rules, normalization rules, dial plans, voice policies, PSTN usage records, voice routes, user enablement, advanced Enterprise Voice features, and call-management features. Use that order as a checklist, while remembering that collocation can change which installation steps are required.
The important distinction is between defining an object and making it participate in call routing. A gateway or trunk may exist in the topology, but calls still depend on normalization, dial-plan interpretation, PSTN usage, voice policy, and route selection. Create a one-page call-flow diagram and annotate where each configuration object is evaluated. This exposes gaps faster than rereading procedure titles.
How does user enablement fit into the solution?
A user is not fully prepared for Enterprise Voice merely because the server-side deployment is complete. Microsoft’s guidance requires enabling the account and ensuring that a unique, normalized primary phone number is placed in the user’s Line URI. The user must also receive a voice policy and dial plan, whether those are inherited globally or at the site level or assigned specifically.
The documented sequence is to enable Enterprise Voice, optionally assign a user-specific voice policy, and optionally assign a user-specific dial plan. Global policies apply by default, while site-level policies apply to users homed at the relevant site. Per-user assignments require the corresponding management-shell procedures. Learn this inheritance model because it explains why a user can have effective settings without an explicit per-user assignment.
A useful lab or paper exercise is to trace three users: one receiving global settings, one receiving site settings, and one receiving explicit per-user settings. For each, identify the effective voice policy, dial plan, and Line URI. The common mistake is to treat optional per-user assignment as mandatory, or to overlook normalization when the phone number appears visually correct.
Which Enterprise Voice and Call Via Work concepts should you separate?
Enterprise Voice and Call Via Work are two on-premises options described by Microsoft, but they solve different transition and telephony problems. Enterprise Voice provides a fuller VoIP feature set through an audio device or VoIP-enabled phone. Call Via Work integrates Skype for Business with an existing PBX and uses the user’s PBX phone for the completed call.
Call Via Work has a more limited feature set than Enterprise Voice. Microsoft specifically notes that it does not support delegation, team call, response group, or Enhanced E9-1-1. Do not merge those capabilities into one feature list. A scenario involving a retained PBX phone, staged migration, or client-controlled PBX calling may point to Call Via Work rather than a full Enterprise Voice user experience.
Remote call control is another boundary worth recording. Microsoft says it is not supported for users homed on Skype for Business Server servers, although it is supported for Skype for Business clients still homed on Lync Server 2013. Treat this as a version and homing distinction, not as a general synonym for Call Via Work.
How should you study routing and normalization?
Study dial plans, normalization rules, voice policies, PSTN usage records, and voice routes as one routing system. A dial plan determines how numbers are interpreted, normalization produces a usable format, voice policy governs permitted calling behavior, PSTN usage links policy to routes, and the route determines the external path. The exact configuration depends on the deployment, but the dependencies should be understood.
Use test numbers on paper rather than memorizing isolated rule examples. Start with the number a user dials, apply the relevant normalization logic, identify the user’s effective dial plan and voice policy, match PSTN usage, and select the route toward a trunk or gateway. If the call fails, state which layer would be checked first and what evidence would confirm the diagnosis.
Microsoft’s user-enablement example shows a normalized Line URI in tel format. That is a reminder that directory identity and telephony identity must be handled deliberately. Keep caller ID translation, called ID translation, normalization, and Line URI in separate notes; combining them under a vague heading such as “phone number formatting” creates avoidable confusion.
What mistakes waste preparation time?
The most damaging mistake is studying an unverified exam listing as though it were current. Confirm the status first. The next is using dumps or leaked-question claims as a substitute for understanding topology and configuration. Such material cannot establish that a candidate can design a resilient voice path, troubleshoot policy inheritance, or apply the documented prerequisites.
Another frequent error is learning commands without learning scope. A command that changes a user property is not equivalent to a topology change, and a per-user policy assignment is not equivalent to a global or site-level policy. Always annotate the object being changed, the role needed, the scope of the change, and the preceding dependency.
Candidates also tend to calculate ports without classifying traffic, choose a branch survivability component without checking WAN and administrator conditions, and assume that a deployed gateway automatically produces a working route. Correct these habits by requiring every answer in your notes to include a condition, a component, and a verification step.
What practical study materials should you build?
Create four working documents: a topology map, a prerequisite and role matrix, a call-routing worksheet, and a fault-isolation checklist. These documents convert Microsoft’s documentation into decision tools. They also reveal whether you understand relationships among components, rather than merely recognizing product terminology.
In the topology map, show Front End, Mediation, PSTN connectivity, Edge services, central sites, branch sites, WAN links, and survivability choices where relevant. In the role matrix, map deployment, voice configuration, and user enablement tasks to the documented administrative roles. In the routing worksheet, trace dialed number, normalized number, policy, PSTN usage, route, trunk, and gateway.
Use the Microsoft Skype for Business Server 2015 documentation as the index for further reading. Its structure covers planning, installation, deployment, configuration, management, and Enterprise Voice. Read the planning material before deployment procedures, and read user enablement after routing concepts. This sequence mirrors the dependencies you would need to reason through in an implementation scenario.
A practical four-stage study roadmap
A staged roadmap works better than repeated broad review: establish the architecture, learn the deployment dependencies, practise configuration reasoning, and then audit gaps against the official documentation. Adjust the pace to your existing Skype for Business experience and to whether you are studying for a live exam or preserving legacy operational knowledge.
Stage one: map the product and voice solution. Read the server documentation overview, then the Enterprise Voice solution and component pages. Explain the difference between Enterprise Voice and Call Via Work, identify Mediation Server responsibilities, and draw a central-site and branch-site call path. Do not begin with command syntax.
Stage two: study planning and prerequisites. Work through sites, regions, WAN links, PSTN connectivity, traffic estimation, survivability, certificates, and administrative roles. Recreate the documented Light traffic, Medium traffic, and Heavy traffic calculations with clearly labeled notes. For every branch scenario, write down the conditions before selecting a survivability design.
Stage three: rehearse deployment and user configuration. Follow the dependency order from topology and Mediation components through gateways, trunks, normalization, dial plans, voice policies, PSTN usage, routes, and user enablement. For each item, record what it enables and what later item depends on it. Trace both inherited and per-user policy assignments.
Stage four: perform a readiness audit. Without looking at notes, explain a complete outbound call path, diagnose a number-normalization problem, choose an administrative role for a user change, and justify a branch design from stated conditions. Reopen the Microsoft pages for every uncertain answer. If the exam is not available, stop treating the audit as a booking countdown and use it as a professional skills assessment.
How should you decide your next action?
Your next action depends on status, not on how many practice questions you can find. First verify whether Microsoft currently offers 70-333 or any certification path that accepts it. If it is unavailable, do not purchase a purported dump or schedule through an unofficial claim; redirect the effort to the official product documentation and a current certification aligned with your role.
If you maintain a Skype for Business Server environment, begin with the topology map and a real change-review checklist, removing sensitive organizational details. Validate component ownership, PSTN paths, administrative roles, user Line URI normalization, policy inheritance, and branch failover assumptions. If you are moving toward newer Microsoft technologies, compare the skills represented here with the current role-based options rather than assuming an old exam maps directly to a new credential.
Use the official retirement announcement for historical certification status and Microsoft Learn’s Skype for Business Server documentation for technical study. Keep a dated record of the availability check because legacy exam information changes in catalogues and third-party sites. The goal is a defensible scheduling decision or, when scheduling is no longer possible, a structured plan for retaining the underlying Enterprise Voice knowledge.
Conclusion
70-333 is best approached as a legacy Enterprise Voice implementation subject whose value depends first on confirmed exam availability and second on the candidate’s technical objective. The strongest preparation is evidence-led: understand the topology, verify prerequisites and administrative scope, follow the deployment dependencies, trace routing and policy inheritance, and test branch and PSTN design decisions against their stated conditions. Use official Microsoft documentation for current status and technical reference, and treat any unofficial question bank as neither a source of requirements nor proof of readiness.
