Multi-Tenant Real-Time Voice AI + RAG Telephony Pipeline

Enterprise voice telephony platform handling real inbound/outbound PSTN calls over Exotel IVR, streaming vector knowledge retrieval with Qdrant, and executing sub-second conversational turns with an 80%+ reduction in end-to-end latency.

Telephony Protocol:SIP / WebSockets (8kHz G.711u)CARRIER_GRADE

TTS Generation Speed:12x Real-Time Factor (RTF)GPU_ACCELERATED

VLLM PagedAttention:Active (Zero OOM in peak loads)STABLE

// REAL-TIME PERFORMANCE METRICSREFRESH_RATE: 1000ms

AVG_TURN_LATENCYLIVE_TELEMETRY

0.0s

Down from ~12s legacy pipeline, 1.5s best case

LATENCY_REDUCTIONLIVE_TELEMETRY

-0%

Aggressive async streaming & TensorRT optimizations

FIRST_CHUNK_ASRLIVE_TELEMETRY

0ms

NVIDIA Riva FastConformer TensorRT engine

CONCURRENT_STREAMSLIVE_TELEMETRY

0ch

Full-duplex WebRTC & Exotel telephony trunks

// TOPOLOGICAL PIPELINE MAP

SYSTEM_PIPELINE_ARCHITECTURE_GRAPH[VOICE-AI_TOPOLOGY]

NODES: ONLINEFLOW: DUPLEX_STREAM

01 // INGESTIONSTEP_1

→Unstructured.io Doc Parsers (PDF/OCR/DOCX)
→Dense BGE-Small/Base Multi-Tenant Embeddings
→Qdrant Vector Cluster (Collection-Isolated)
→PostgreSQL Metadata & ACL Ledger

SENSOR / INFLOWSTANDBY

02 // INFERENCE & PROCESSINGSTEP_2

→NVIDIA Riva FastConformer TensorRT ASR (~150ms)
→IndicTrans2 1B (Hindi ↔ English Bidirectional)
→Qwen2.5-7B-Instruct-GPTQ-Int4 (vLLM Engine)
→Continuous Batching & PagedAttention KV-Cache
→FastPitch / Tacotron2 Low-Latency Neural TTS

ACCELERATED_COREACTIVE_NODE

03 // TRANSPORT & BUSSTEP_3

→Exotel PSTN Telephony Trunk (8kHz µ-law audio)
→Full-Duplex WebRTC & Fast Binary WebSockets
→FastAPI Async Event Gateway & Health Monitors
→Redis Session Store & Conversation Turn Buffers

LOW_LATENCYSTANDBY

04 // CLIENT & INTERFACESSTEP_4

→LiveKit WebRTC Agent Integration Layer
→Real-Time Telephony Diagnostic Stream Dashboard
→IVR Automated Action Dispatcher (Calendaring/CRM)
→Bhashini Cloud API Automated Failover Router

TELEMETRY_OUTSTANDBY

DATA_BUS:G.711u / WebSocket / Async Event Loop

CLICK_NODE_TO_INSPECT_VECTOR_STATE

$ cat /etc/manifests/voice-ai.json

ENCODING: UTF-8

{
  "project_id": "voice-ai",
  "status": "PRODUCTION_ACTIVE",
  "timeframe": "2025 - 2026",
  "pipeline_stages": {
    "ingestion": [
      "Unstructured.io Doc Parsers (PDF/OCR/DOCX)",
      "Dense BGE-Small/Base Multi-Tenant Embeddings",
      "Qdrant Vector Cluster (Collection-Isolated)",
      "PostgreSQL Metadata & ACL Ledger"
    ],
    "inference": [
      "NVIDIA Riva FastConformer TensorRT ASR (~150ms)",
      "IndicTrans2 1B (Hindi ↔ English Bidirectional)",
      "Qwen2.5-7B-Instruct-GPTQ-Int4 (vLLM Engine)",
      "Continuous Batching & PagedAttention KV-Cache",
      "FastPitch / Tacotron2 Low-Latency Neural TTS"
    ],
    "transport": [
      "Exotel PSTN Telephony Trunk (8kHz µ-law audio)",
      "Full-Duplex WebRTC & Fast Binary WebSockets",
      "FastAPI Async Event Gateway & Health Monitors",
      "Redis Session Store & Conversation Turn Buffers"
    ],
    "client": [
      "LiveKit WebRTC Agent Integration Layer",
      "Real-Time Telephony Diagnostic Stream Dashboard",
      "IVR Automated Action Dispatcher (Calendaring/CRM)",
      "Bhashini Cloud API Automated Failover Router"
    ]
  },
  "telemetry": {
    "AVG_TURN_LATENCY": "2.4s",
    "LATENCY_REDUCTION": "-80%",
    "FIRST_CHUNK_ASR": "150ms",
    "CONCURRENT_STREAMS": "128ch"
  }
}

JOURNALCTL_OUTPUT_LOGS :: VOICE-AI

LEVEL: INFO / DIAGNOSTIC

01[2026-01-14 09:22:10.104] TELEPHONY_INGEST: Exotel PSTN trunk connected (8kHz µ-law audio payload)

02[2026-01-14 09:22:10.252] RIVA_ASR: FastConformer transcribed first chunk in 148ms [LANG: HINDI/HIN_ENG]

03[2026-01-14 09:22:10.364] NMT_TRANSLATE: IndicTrans2-1B translated inbound utterance to EN (112ms)

04[2026-01-14 09:22:10.402] VECTOR_SEARCH: Qdrant retrieved top-3 corpus contexts (score: 0.912, 38ms)

05[2026-01-14 09:22:10.567] VLLM_CORE: Qwen2.5-7B TTFT reached 165ms; first token streamed to TTS buffer

06[2026-01-14 09:22:10.747] TTS_SYNTH: FastPitch generated 24kHz synthesized audio frame (180ms)

07[2026-01-14 09:22:10.748] AUDIO_OUT: Full turn completed in 644ms (Well within 1.5s real-time target)

08[2026-01-14 09:22:11.002] TOOL_DISPATCH: CRM appointment confirmed & WhatsApp notification queued

// SUBSYSTEM ENGINEERING SPECIFICATIONS

>1. Elimination of Sequential REST Latency

▪Replaced multi-hop third-party HTTP endpoints with colocated self-hosted Docker containers on AWS EC2 GPU instances.
▪Implemented pipelined streaming: TTS synthesis begins streaming audio chunks before LLM completes the full sentence.
▪Migrated from faster-whisper (~400ms) to TensorRT-optimized NVIDIA Riva (~150ms).

>2. Multilingual Telephony Optimization

▪Standardized Exotel IVR 8kHz audio resampled in memory for Riva ASR with zero file-system writes.
▪Integrated IndicTrans2 with Bhashini API failover for robust Hindi and Indian English translation.
▪Qdrant collection isolation ensuring multi-tenant data privacy across medical and commercial clients.

← Return to System DashboardTERMINAL_NODE: 0xvoice-ai [STABLE]