Outbound Calling Glossary

Calling & Dialers

Predictive dialer — A dialer mode that uses an algorithm to place more calls than there are available agents, banking on the statistical likelihood that not all calls will connect simultaneously. The dialer adjusts the dial rate in real time based on agent availability, average handle time, and connect rate. Aggressive predictive pacing increases contact rate but also raises abandonment rate — a key metric regulators watch.

Power dialer — Dials one call per available agent at a time. Slower than predictive but produces zero calls that reach a live person before an agent is ready. Preferred by teams operating in jurisdictions with strict abandonment rate caps.

Preview dialer — Presents the agent with a contact record before dialing begins. The agent reviews the record and manually triggers the call (or skips). Used for high-value accounts, complex sales, or any call where preparation before pickup matters more than volume.

Progressive dialer — Hybrid between power and preview. The system waits for agent availability, then automatically dials the next contact — no manual trigger, but no over-dialing. Abandonment rate is near zero.

Press-1 / blast dialer — Delivers a pre-recorded message and invites the recipient to press a digit to connect to a live agent. Regulated differently from live-agent outbound in most jurisdictions.

ASR (Answer-Seizure Ratio) — The percentage of call attempts that result in a live answer. ASR = answered calls ÷ total attempted calls × 100. A healthy outbound campaign typically targets ASR above 30%; lower values suggest number reputation problems, bad data, or aggressive pacing.

ACD (Automatic Call Distributor) — Routes inbound or transferred calls to the next available agent based on rules (round-robin, skill-based, priority queue). Most outbound contact center platforms include an ACD for handling transfers and inbound callbacks.

Abandonment rate — The percentage of connected calls where no agent was available and the call was dropped before the party was served. The FTC's Telemarketing Sales Rule sets a 3% cap on abandonment for US consumer outbound campaigns. Predictive dialers require active monitoring to stay within this limit.

AMD (Answering Machine Detection) — A signal-processing feature that attempts to classify a connected call as a live human or voicemail before an agent is bridged. AMD adds 1–3 seconds of post-answer delay and is not perfectly accurate — false positives drop live calls, false negatives waste agent time. Most dialer platforms expose an AMD sensitivity setting.

Wrap-up time — The time an agent spends on post-call work (logging notes, updating the CRM, scheduling a callback) before becoming available for the next call. Shorter wrap-up time increases agent utilization. Dialers calculate average wrap-up time when computing optimal dial rate.

Concurrency / channels — The maximum number of simultaneous call legs a trunk or account can carry. UnlimCall's flat seat rate includes a defined channel allocation per seat — typically 1–2 concurrent calls per active agent seat, scalable by request.

Local presence dialing — Presenting a caller ID with an area code that matches (or is near) the recipient's own area code. Increases answer rates in markets where calls from unfamiliar area codes are routinely ignored. UnlimCall provisions local-format DIDs on demand across supported markets.

Caller ID & Deliverability

DID (Direct Inward Dialing) — A telephone number assigned to a trunk that can be used for both inbound and outbound identification. In outbound calling, a DID serves as the caller ID presented to the called party.

Caller ID (CLI / ANI) — The number displayed on the recipient's phone when a call arrives. CLI (Calling Line Identification) is the European term; ANI (Automatic Number Identification) is North American. Carriers validate that the presented number is assigned to the originating party.

CNAM (Calling Name) — A database lookup that maps a phone number to a business or person name, displayed alongside the number on compatible handsets. CNAM databases are maintained by third parties in the US; they are updated by number owners and queried by the terminating carrier at its discretion. Delivery is not guaranteed on mobile networks.

Number reputation — An aggregated score assigned to a phone number by analytics platforms (Hiya, First Orion, Transaction Network Services) based on call volume, complaint rate, and behavioral patterns. A number with poor reputation may be labeled "Spam Likely" or "Scam Likely" on the called party's display, dramatically reducing answer rates.

Spam labeling — When a terminating carrier or device analytics service flags an outbound number and overlays a warning label on the recipient's screen. Spam labels are applied algorithmically and can be contested through carrier portals, but the process is slow. Rotating caller IDs and maintaining low abandonment rates help reduce labeling risk.

Number rotation — The practice of distributing outbound calls across a pool of DIDs to reduce per-number call velocity and slow the accumulation of spam complaints on any single number.

SIP & Network

SIP trunk — A virtual phone line delivered over IP using the Session Initiation Protocol. Replaces physical PRI or analog lines. SIP trunks connect a PBX or dialer to a carrier's network; the carrier routes the call to the PSTN. UnlimCall provides SIP trunks on a flat per-seat basis with no per-minute charges.

SIP (Session Initiation Protocol) — The signaling protocol used to establish, manage, and terminate voice and video calls over IP networks. SIP handles call setup; the actual audio is carried by RTP (Real-time Transport Protocol) on a separate media path.

Codec — The algorithm used to encode and compress audio for transmission over IP. The two most common codecs in outbound contact centers are G.711 (uncompressed, high quality, higher bandwidth) and OPUS (compressed, adaptable, lower bandwidth). UnlimCall's edge supports both.

G.711 — The ITU standard codec for uncompressed voice audio. Available as G.711u (mu-law, used in North America and Japan) and G.711a (A-law, used in Europe and most other markets). Requires 64 kbps per call leg. Preferred for call center use where audio quality directly affects agent performance.

OPUS — An open, royalty-free audio codec designed for variable-bandwidth networks. Well-suited for agents on broadband connections in markets where G.711 bandwidth is a constraint.

Jitter — Variation in packet arrival times on a network. High jitter causes choppy or robotic audio. Jitter buffers in SIP endpoints compensate by introducing a small playback delay. UnlimCall's edge-to-edge latency target is under 50ms to minimize jitter at the network boundary.

Latency — The one-way delay from audio source to audio playback. End-to-end latency under 150ms is generally imperceptible to callers; above 300ms creates noticeable conversation delays. Measured in milliseconds (ms).

RTP (Real-time Transport Protocol) — The protocol that carries actual audio (and video) between endpoints after SIP has established the call. RTP packets are sent UDP by default.

POP (Point of Presence) — A physical network node where a carrier terminates SIP connections and hands traffic to the PSTN or to peering partners. UnlimCall operates multiple regional POPs to keep audio latency below 50ms for agents in any of the 33 supported markets.

Compliance

TCPA (Telephone Consumer Protection Act) — US federal law governing outbound telephone marketing. Relevant provisions include restrictions on calling hours, required disclosures, do-not-call list compliance, and consent requirements for autodialed calls to mobile numbers. UnlimCall's network is designed to support TCPA-compliant operations; customers are responsible for their own compliance posture and legal counsel.

DNC (Do Not Call) — Refers to both the US National Do Not Call Registry (maintained by the FTC) and internal suppression lists maintained by individual companies. Outbound campaigns are expected to scrub contact lists against applicable DNC registries before dialing. Many dialer platforms include DNC scrubbing integrations.

STIR/SHAKEN — A call authentication framework (Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs) mandated for US and Canadian carriers. See the STIR/SHAKEN guide for a full explanation.

Robocall mitigation — The set of network-level and operational practices carriers use to reduce unwanted automated calls. In the US, carriers must file a Robocall Mitigation Database certification and implement STIR/SHAKEN or an approved alternative. UnlimCall's US/CA origination infrastructure operates within this framework.

GDPR (General Data Protection Regulation) — EU/EEA data protection law that governs the processing of personal data, including call recordings and contact records. Applies to any outbound operation targeting EU residents regardless of where the calling company is incorporated.