3gpp-mcp-server/docs/limitations-and-issues.md

MCP Server for querying 3GPP telecom protocol specifications

# Current Limitations & Known Issues

## Overview

This document provides a comprehensive overview of the current limitations, known issues, and areas for improvement in the 3GPP MCP Server. Understanding these constraints is essential for users, developers, and stakeholders to set appropriate expectations and plan future enhancements.

## Current Implementation Limitations

### **Search & Query Limitations**

#### Text-Only Search Intelligence
**Limitation**: Current search is based on keyword matching and basic text analysis without semantic understanding.

**Impact**:
- Queries like "authentication procedures" may miss specifications that discuss authentication using different terminology
- No understanding of technical concept relationships (e.g., NAS ↔ security context)
- Limited ability to answer conceptual questions that require synthesis across multiple specifications

**Example Issues**:
```
Query: "How does 5G improve security over 4G?"
Current Response: Lists specifications containing "5G" and "security"
Desired Response: Comparative analysis of 4G vs 5G security improvements
```

**Workaround**: Use specific technical terms and specification series filters for more targeted results.

**Timeline for Fix**: Version 1.1 (March 2025) - Vector search implementation

#### Limited Cross-Reference Understanding
**Limitation**: Cannot deeply understand relationships between specifications or track dependencies.

**Impact**:
- "Find related specs" tool provides basic keyword-based relationships only
- No understanding of which specifications are prerequisites for others
- Cannot identify circular dependencies or conflicts between specifications

**Example Issues**:
- Query about "RRC procedures" doesn't automatically include related PDCP/RLC specs
- Evolution queries can't track how changes in one spec affect dependent specifications

**Timeline for Fix**: Version 1.2 (June 2025) - Cross-specification analysis engine

### **Dataset & Content Limitations**

#### Mock Data Default
**Limitation**: Ships with mock data by default; full TSpec-LLM dataset is optional.

**Impact**:
- Limited specification coverage in default installation
- Responses are generic and may not reflect actual specification content
- No access to real specification text for detailed analysis

**Current Mock Data Coverage**:
- 3 sample specifications (TS 24.301, TS 36.331, TS 38.331)
- 2 sample protocols (NAS, RRC) with basic procedures
- Generic responses for most queries

**Workaround**: Download and configure TSpec-LLM dataset (13.5GB) for full functionality.

**Timeline for Fix**: Ongoing - Better dataset integration and partial download options

#### Static Dataset
**Limitation**: No real-time updates from 3GPP; relies on periodic TSpec-LLM dataset updates.

**Impact**:
- May not include latest specification versions or new releases
- Cannot track live changes or provide notifications about specification updates
- Version information may be outdated

**Current Dataset Coverage**: 3GPP Releases 8-19 (as of TSpec-LLM v2.0, April 2025)

**Timeline for Fix**: Version 2.0+ (2026) - Real-time specification monitoring

#### Limited Format Support
**Limitation**: Primarily designed for TSpec-LLM processed markdown; limited native format support.

**Impact**:
- Cannot directly process original PDF specifications from 3GPP
- DOCX support is basic and may miss formatting/diagrams
- No support for specification diagrams or technical figures

**Supported Formats**:
- ✅ Markdown (.md) - Primary format
- ⚠️ DOCX (.docx) - Basic text extraction only
- ❌ PDF - Not supported directly
- ❌ Original 3GPP Word documents - Not supported

**Timeline for Fix**: Version 1.2+ - Enhanced document processing

### **Performance & Scalability Limitations**

#### Memory Usage
**Limitation**: Current implementation loads specification metadata into memory, which can be substantial with large datasets.

**Current Memory Usage**:
- Baseline (no dataset): ~50MB
- With mock data: ~100MB
- With full TSpec-LLM dataset: ~1.5-2GB (estimated)

**Impact**:
- May not run on low-memory systems
- Startup time increases with dataset size
- Memory usage grows with concurrent queries

**Workaround**: Increase system memory allocation, limit concurrent operations.

**Timeline for Fix**: Version 1.1-1.2 - Memory optimization and streaming

#### Single-Instance Deployment
**Limitation**: Not designed for horizontal scaling or load balancing.

**Impact**:
- Single point of failure
- Cannot handle high concurrent loads
- No built-in redundancy or failover

**Current Capacity**:
- Estimated max concurrent users: ~50
- Max queries per minute: ~200
- Response time degrades with load

**Timeline for Fix**: Version 1.3 (September 2025) - Enterprise scaling features

#### Cold Start Performance
**Limitation**: Initial startup time can be significant with large datasets.

**Current Startup Times**:
- Mock data: ~2 seconds
- Partial dataset (~1GB): ~30 seconds
- Full dataset (~13.5GB): ~2-5 minutes (estimated)

**Timeline for Fix**: Version 1.1-1.2 - Lazy loading and indexing improvements

### **Feature & Functionality Limitations**

#### Basic Response Generation
**Limitation**: Responses are primarily templated text without advanced natural language generation.

**Impact**:
- Cannot generate complex explanations or tutorials
- Limited ability to synthesize information from multiple sources
- No support for different explanation levels (beginner vs expert)

**Example Limitations**:
- Cannot generate step-by-step implementation guides
- Cannot create comparative analyses between specifications
- Cannot adapt response complexity to user expertise level

**Timeline for Fix**: Version 1.2+ - Advanced NLG capabilities

#### No Diagram or Visual Support
**Limitation**: Cannot process, generate, or display technical diagrams.

**Impact**:
- Missing crucial visual information from specifications
- Cannot explain procedures with message flow diagrams
- No support for protocol stack visualizations

**Timeline for Fix**: Version 2.0+ - Visual content processing and generation

#### Limited Integration Options
**Limitation**: Primary integration is through Claude Desktop; limited API options.

**Current Integration Support**:
- ✅ Claude Desktop (MCP STDIO)
- ❌ REST API wrapper
- ❌ WebSocket interface
- ❌ gRPC service
- ❌ Web UI

**Timeline for Fix**: Version 1.3+ - API extensions and web interfaces

## Known Issues

### **Critical Issues** (Must Fix)

#### Issue #1: Large Dataset Memory Spikes
**Description**: Memory usage can spike during large dataset initialization, potentially causing system instability.

**Symptoms**:
- Server crashes with "out of memory" errors
- Slow response times during initialization
- System becomes unresponsive with large datasets

**Affected Versions**: All current versions
**Workaround**: Increase Node.js memory limit using `--max-old-space-size=8192`
**Priority**: High
**Target Fix**: Version 1.1

#### Issue #2: Unicode Handling in Specifications
**Description**: Some specifications contain special Unicode characters that are not properly handled.

**Symptoms**:
- Garbled text in search results
- Search failures for terms with special characters
- Encoding errors in response formatting

**Affected Content**: Specifications with mathematical symbols, special formatting
**Workaround**: Use ASCII-only search terms when possible
**Priority**: Medium
**Target Fix**: Version 1.1

### **Performance Issues**

#### Issue #3: Slow Initial Search on Large Datasets
**Description**: First search query can be very slow on large datasets due to lazy loading.

**Symptoms**:
- First query takes 10-30 seconds
- Subsequent queries are much faster
- Timeout errors on very large datasets

**Affected Configurations**: Full TSpec-LLM dataset installations
**Workaround**: Perform a dummy search during initialization
**Priority**: Medium
**Target Fix**: Version 1.1

#### Issue #4: Memory Leaks in Long-Running Sessions
**Description**: Memory usage gradually increases over time during long sessions.

**Symptoms**:
- Memory usage grows after each query
- Degraded performance over time
- Eventually requires server restart

**Affected Usage**: High-volume or long-running deployments
**Workaround**: Regular server restarts, monitor memory usage
**Priority**: Medium
**Target Fix**: Version 1.2

### **Usability Issues**

#### Issue #5: Error Messages Lack Context
**Description**: Error messages don't provide sufficient context for troubleshooting.

**Symptoms**:
- Generic "Error occurred" messages
- No guidance on how to resolve issues
- Difficult to diagnose configuration problems

**Example**:
```
Current: "Error: Specification not found"
Better: "Error: Specification 'TS 99.999' not found. Available series: 21, 22, 24, 36, 38"
```

**Priority**: Low
**Target Fix**: Version 1.1

#### Issue #6: Limited Search Result Context
**Description**: Search results don't provide enough context about why a specification was matched.

**Current Behavior**:
```
Found 5 specifications matching "authentication":
- TS 24.301 (Relevance: 75%)
- TS 33.501 (Relevance: 68%)
```

**Desired Behavior**:
```
Found 5 specifications matching "authentication":
- TS 24.301 (75%) - Matched: "authentication procedures" in section 5.4
- TS 33.501 (68%) - Matched: "5G authentication" in title, "AKA protocol" in keywords
```

**Priority**: Medium
**Target Fix**: Version 1.1

## Browser and Client Compatibility

### **Claude Desktop Compatibility**
- ✅ **macOS**: Fully supported on macOS 12+
- ✅ **Windows**: Supported on Windows 10/11
- ⚠️ **Linux**: Supported but limited testing
- ❌ **Chrome OS**: Not tested

### **Node.js Compatibility**
- ✅ **Node.js 18**: Fully supported
- ✅ **Node.js 20**: Recommended version
- ⚠️ **Node.js 22**: Should work but not tested
- ❌ **Node.js 16**: Not supported (EOL)

### **Operating System Compatibility**
- ✅ **Ubuntu 20.04+**: Primary development platform
- ✅ **macOS 12+**: Well tested
- ✅ **Windows 10/11**: Supported with WSL2 recommended
- ⚠️ **CentOS/RHEL**: Should work but not tested
- ❌ **Windows 7/8**: Not supported

## Development & Maintenance Limitations

### **Code Quality Issues**

#### Limited Test Coverage
**Current State**: ~40% test coverage
**Target**: >90% test coverage
**Missing Areas**:
- Integration tests for full query workflows
- Performance tests for large datasets
- Error handling edge cases
- Mock data consistency tests

#### Documentation Gaps
**Current State**: Comprehensive user documentation, limited developer docs
**Missing Documentation**:
- Internal API documentation
- Contribution guidelines
- Code architecture deep-dives
- Performance tuning guides

### **Development Workflow Limitations**

#### Manual Dataset Management
**Limitation**: No automated pipeline for dataset updates or validation.

**Impact**:
- Manual effort required to integrate new TSpec-LLM releases
- No validation that dataset changes don't break functionality
- Difficult to test with different dataset versions

#### Limited CI/CD Pipeline
**Current State**: Basic build and test automation
**Missing Elements**:
- Automated performance testing
- Integration testing with real datasets
- Automated security scanning
- Deployment automation

## Security Considerations

### **Current Security Limitations**

#### No Authentication or Authorization
**Limitation**: Server runs with no access controls or user management.

**Risk Level**: Medium (for development), High (for production)
**Impact**: Anyone with access to the server can query all specifications
**Timeline for Fix**: Version 1.3 - Enterprise security features

#### Input Validation Gaps
**Limitation**: Limited input sanitization and validation.

**Potential Risks**:
- Path traversal attacks (low risk - read-only access)
- Resource exhaustion through large queries
- Malformed input causing crashes

**Timeline for Fix**: Version 1.1 - Enhanced input validation

#### No Rate Limiting
**Limitation**: No protection against excessive queries or abuse.

**Risk Level**: Medium
**Impact**: Server can be overwhelmed by rapid queries
**Timeline for Fix**: Version 1.3 - Rate limiting implementation

## Workarounds & Mitigation Strategies

### **Memory Management**
```bash
# Increase Node.js memory limit
export NODE_OPTIONS="--max-old-space-size=8192"

# Monitor memory usage
while true; do
  ps aux | grep node | grep -v grep
  sleep 60
done
```

### **Performance Optimization**
```bash
# Use smaller dataset for development
cd data/TSpec-LLM
rm -rf Rel-{8,9,10,11,12,13,14}  # Keep only recent releases

# Enable caching
export CACHE_ENABLED=true
export CACHE_SIZE=5000
```

### **Search Query Optimization**
```typescript
// Use specific technical terms
"NAS authentication procedure"  // Better than "how does auth work"

// Filter by series for targeted results
{
  query: "security procedures",
  series: ["33"],  // Security specifications
  limit: 10
}

// Use specification IDs when known
"TS 24.501 authentication"  // More specific than generic terms
```

### **Deployment Best Practices**
```yaml
# Docker deployment with resource limits
version: '3.8'
services:
  3gpp-server:
    image: 3gpp-mcp-server:latest
    deploy:
      resources:
        limits:
          memory: 4G
          cpus: '2.0'
        reservations:
          memory: 2G
          cpus: '1.0'
    restart: unless-stopped
```

## Reporting Issues

### **Bug Reports**
When reporting bugs, please include:
1. **Environment**: OS, Node.js version, dataset configuration
2. **Steps to Reproduce**: Exact queries or actions that cause the issue
3. **Expected vs Actual Behavior**: What should happen vs what actually happens
4. **Logs**: Any error messages or console output
5. **Dataset Information**: Mock data vs TSpec-LLM, size, version

### **Feature Requests**
For new features, please describe:
1. **Use Case**: What problem would this feature solve?
2. **User Story**: As a [user type], I want to [action] so that [benefit]
3. **Priority**: How important is this feature to your workflow?
4. **Implementation Ideas**: Any technical approaches you'd suggest

### **Performance Issues**
For performance problems, please provide:
1. **System Specifications**: RAM, CPU, storage type
2. **Dataset Size**: Which specifications are loaded
3. **Query Patterns**: Types and frequency of queries
4. **Metrics**: Response times, memory usage, error rates
5. **Load Profile**: Number of concurrent users/queries

Understanding these limitations helps set realistic expectations and guides the development roadmap toward a more robust, enterprise-ready solution.