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1.3 Application Requirements

Document Information

Item Details
Document Version 1.0
Last Updated December 2025
Author Network Architecture Team
Organization Abhavtech.com
Classification Internal Use Only

1.3.1 Overview

This section documents the network requirements for all business-critical applications at Abhavtech.com. Understanding application behavior, dependencies, and performance requirements is essential for designing effective SD-WAN policies, Application-Aware Routing (AAR), and Quality of Service (QoS) configurations.

Objectives

  • Catalog all applications requiring WAN connectivity
  • Define performance SLAs for each application class
  • Document application dependencies and traffic patterns
  • Map applications to SD-WAN QoS classes
  • Establish application-specific routing requirements

1.3.2 Application Classification Framework

Application Criticality Tiers

                    APPLICATION CRITICALITY PYRAMID
                    ===============================

                           ╱╲
                          ╱  ╲
                         ╱ T1 ╲        Tier 1: Mission Critical
                        ╱──────╲       - Revenue-impacting
                       ╱   T2   ╲      - No acceptable downtime
                      ╱──────────╲     
                     ╱    T3      ╲    Tier 2: Business Critical
                    ╱──────────────╲   - Productivity-impacting
                   ╱      T4        ╲  - Limited downtime acceptable
                  ╱──────────────────╲ 
                 ╱       T5           ╲ Tier 3: Business Important
                ╱──────────────────────╲ - Important but not critical
                                        - Degradation acceptable

                                        Tier 4: Best Effort
                                        - Standard business apps

                                        Tier 5: Scavenger
                                        - Non-critical, background

Criticality Tier Definitions

Tier Name RPO RTO Downtime Cost Examples
T1 Mission Critical 0 <15 min >$XXXK/hour Voice, Trading, Payment
T2 Business Critical <1 hr <1 hr $XX-XXXK/hour SAP, Core DB
T3 Business Important <4 hr <4 hr $X-XXK/hour Email, CRM
T4 Best Effort <24 hr <24 hr <$XK/hour Web browsing
T5 Scavenger N/A N/A Minimal Updates, Backup

1.3.3 Tier 1: Mission Critical Applications

Voice and Unified Communications

Parameter Requirement
Application Cisco Unified CM, Webex Calling
Protocol SIP (UDP 5060-5061), RTP (UDP 16384-32767)
Bandwidth per call 64 Kbps (G.711), 24 Kbps (G.729)
Concurrent calls 500 (Mumbai), 200 (branches)
Latency <75 ms one-way
Jitter <30 ms
Packet Loss <1%
MOS Score >4.0
Availability 99.999%

Voice Traffic Flow

                         VOICE TRAFFIC ARCHITECTURE
    ═══════════════════════════════════════════════════════════════════

    ┌──────────────┐     SIP Signaling     ┌──────────────┐
    │   IP Phone   │◄────────────────────►│    CUCM      │
    │  Branch Site │     (UDP 5060)        │  Mumbai DC   │
    └──────┬───────┘                       └──────────────┘
           │ RTP Media (Local if same site, WAN if remote)
           │ UDP 16384-32767
    ┌──────▼───────┐
    │  Remote IP   │
    │    Phone     │
    └──────────────┘

    QoS Marking:
    - SIP Signaling: DSCP CS3 (24)
    - RTP Media: DSCP EF (46)

Video Conferencing

Parameter Webex MS Teams
Protocol HTTPS/UDP HTTPS/UDP
Ports 443, 9000, 5004 443, 3478-3481
Bandwidth (720p) 1.5 Mbps 1.5 Mbps
Bandwidth (1080p) 3.0 Mbps 3.0 Mbps
Latency <100 ms <100 ms
Jitter <30 ms <30 ms
Packet Loss <1% <1%
Concurrent sessions 150 200

1.3.4 Tier 2: Business Critical Applications

SAP ERP/S4HANA

Parameter Requirement
Application SAP S/4HANA, SAP GUI, Fiori
Protocol RFC (TCP 3300-3399), HTTPS (443)
Server Location Mumbai DC (Primary), Chennai DR
Users 1,800
Bandwidth 50-100 Mbps sustained
Latency <150 ms round-trip
Jitter <50 ms
Packet Loss <0.5%
Session Timeout 30 minutes

SAP Traffic Pattern

    ┌────────────────────────────────────────────────────────────────┐
    │                     SAP TRAFFIC PATTERNS                       │
    ├────────────────────────────────────────────────────────────────┤
    │                                                                │
    │  Morning Login Spike (08:00-09:30):                           │
    │  ████████████████████████ 180 Mbps                            │
    │                                                                │
    │  Steady State (09:30-17:00):                                  │
    │  ███████████████ 120 Mbps                                     │
    │                                                                │
    │  Month-End Close (Last 3 days):                               │
    │  ██████████████████████████████ 220 Mbps                      │
    │                                                                │
    │  After Hours (17:00-08:00):                                   │
    │  ████ 35 Mbps                                                 │
    │                                                                │
    └────────────────────────────────────────────────────────────────┘

Database Replication

Parameter Requirement
Application Oracle Data Guard, SQL Always-On
Protocol Oracle Net (TCP 1521), SQL (TCP 1433)
Replication Type Synchronous (Local), Async (DR)
Bandwidth 100-150 Mbps sustained
Latency <25 ms (sync), <100 ms (async)
Packet Loss <0.1% (critical for sync)
Recovery Point Zero data loss (sync)

Core Banking Application

Parameter Requirement
Application Finacle Core Banking
Protocol HTTPS (443), Custom (8080)
Server Location Mumbai DC
Users 450
Transactions/sec 150 TPS peak
Latency <100 ms
Availability 99.99%

1.3.5 Tier 3: Business Important Applications

Office 365 Suite

Component Protocol Ports Bandwidth Latency Notes
Exchange Online HTTPS 443 50 Kbps/user <150 ms Email, calendar
SharePoint HTTPS 443 Variable <200 ms Document access
OneDrive HTTPS 443 Variable <200 ms Sync traffic
Teams (Chat) HTTPS 443 20 Kbps/user <200 ms Messaging

Office 365 Optimization Strategy

    ┌────────────────────────────────────────────────────────────────┐
    │              OFFICE 365 CLOUD ONRAMP STRATEGY                 │
    ├────────────────────────────────────────────────────────────────┤
    │                                                                │
    │  CURRENT PATH (via DC):                                       │
    │  Branch → MPLS → Mumbai DC → Internet → O365                  │
    │  Latency: 85-120ms                                            │
    │                                                                │
    │  OPTIMIZED PATH (Direct Internet Access):                     │
    │  Branch → Local Internet → O365 (nearest Microsoft PoP)       │
    │  Latency: 35-55ms                                             │
    │                                                                │
    │  IMPLEMENTATION:                                              │
    │  - Enable Cloud OnRamp for SaaS                               │
    │  - Configure O365 domains in trusted list                     │
    │  - Apply QoS for real-time components (Teams voice/video)     │
    │  - Monitor via vAnalytics cloud application metrics           │
    │                                                                │
    └────────────────────────────────────────────────────────────────┘

Salesforce CRM

Parameter Requirement
Application Salesforce Sales Cloud, Service Cloud
Protocol HTTPS (443)
Instance ap3.salesforce.com (Singapore)
Users 450
Bandwidth 15-25 Mbps peak
Latency <150 ms
Availability 99.9% (SaaS SLA)

ServiceNow ITSM

Parameter Requirement
Application ServiceNow Utah
Protocol HTTPS (443)
Instance abhavtech.service-now.com
Users 380
Bandwidth 8-12 Mbps peak
Latency <200 ms

1.3.6 Application to QoS Mapping

SD-WAN QoS Class Mapping

Application Traffic Class DSCP Queue Priority Bandwidth %
Voice (RTP) Real-Time EF (46) Priority Queue 10%
Voice (SIP) Call Signaling CS3 (24) Queue 1 2%
Video Conference Real-Time AF41 (34) Queue 1 15%
SAP Interactive Business Critical AF31 (26) Queue 2 25%
Database Replication Business Critical AF21 (18) Queue 2 15%
Office 365 Business Important AF11 (10) Queue 3 15%
Web Browsing Default BE (0) Default Queue 10%
File Transfer Bulk Data AF12 (12) Queue 4 5%
Backup Scavenger CS1 (8) Queue 5 3%

QoS Policy Diagram

                         SD-WAN QoS QUEUE MODEL
    ═══════════════════════════════════════════════════════════════

    ┌─────────────────────────────────────────────────────────────┐
    │                     TRAFFIC INGRESS                         │
    │    Application Recognition (NBAR2) + DPI                    │
    └────────────────────────────┬────────────────────────────────┘
    ┌─────────────────────────────────────────────────────────────┐
    │                  CLASSIFICATION & MARKING                   │
    │  ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌───────┐ │
    │  │Voice/RTP│ │  Video  │ │   SAP   │ │  O365   │ │Default│ │
    │  │ DSCP EF │ │DSCP AF41│ │DSCP AF31│ │DSCP AF11│ │DSCP BE│ │
    │  └────┬────┘ └────┬────┘ └────┬────┘ └────┬────┘ └───┬───┘ │
    └───────┼───────────┼───────────┼───────────┼──────────┼─────┘
            │           │           │           │          │
            ▼           ▼           ▼           ▼          ▼
    ┌─────────────────────────────────────────────────────────────┐
    │                    QUEUING & SCHEDULING                     │
    │                                                             │
    │  ┌─────────┐  Priority Queue (LLQ) - 10%                   │
    │  │ Voice   │  - Strict priority                            │
    │  │   RTP   │  - Policed at 10% interface                   │
    │  └─────────┘                                               │
    │                                                             │
    │  ┌─────────┐  CBWFQ Queue 1 - 15%                          │
    │  │  Video  │  - Weighted fair queuing                      │
    │  │Conference│ - Guaranteed minimum                         │
    │  └─────────┘                                               │
    │                                                             │
    │  ┌─────────┐  CBWFQ Queue 2 - 40%                          │
    │  │Business │  - SAP, Database, Core Apps                   │
    │  │Critical │  - Largest allocation                         │
    │  └─────────┘                                               │
    │                                                             │
    │  ┌─────────┐  Default Queue - 35%                          │
    │  │ Default │  - Best effort traffic                        │
    │  │ + Bulk  │  - Includes scavenger                        │
    │  └─────────┘                                               │
    │                                                             │
    └─────────────────────────────────────────────────────────────┘

1.3.7 Application SLA Requirements Matrix

Complete SLA Matrix

Application Latency (ms) Jitter (ms) Loss (%) Availability QoS Class
Voice (VoIP) <75 <30 <1.0 99.999% Real-Time
Video Conf <100 <30 <1.0 99.99% Real-Time
SAP GUI <150 <50 <0.5 99.99% Business Critical
SAP Fiori <200 <100 <1.0 99.99% Business Critical
Database Sync <25 <10 <0.1 99.999% Business Critical
Database Async <100 <50 <0.5 99.99% Business Critical
Core Banking <100 <30 <0.5 99.99% Business Critical
Office 365 <150 <100 <1.0 99.9% Business Important
Salesforce <150 <100 <1.0 99.9% Business Important
Web Browsing <300 N/A <2.0 99.5% Best Effort
File Transfer N/A N/A <0.5 99.5% Bulk Data
Backup N/A N/A <0.1 99.0% Scavenger

Application-Aware Routing (AAR) SLA Classes

SLA Class Latency Threshold Loss Threshold Jitter Threshold Fallback Action
Real-Time 100 ms 1% 30 ms Switch path immediately
Critical 150 ms 2% 50 ms Switch within 1 sec
Important 250 ms 3% 100 ms Switch within 5 sec
Best Effort 500 ms 5% N/A No automatic switch

1.3.8 Application Dependencies

Application Dependency Map

                    APPLICATION DEPENDENCY MATRIX
    ═══════════════════════════════════════════════════════════════

    ┌─────────────────────────────────────────────────────────────┐
    │                                                             │
    │  ┌─────────┐      ┌─────────┐      ┌─────────┐             │
    │  │   SAP   │─────►│   DNS   │◄─────│  O365   │             │
    │  │  S/4H   │      │Infoblox │      │         │             │
    │  └────┬────┘      └────┬────┘      └────┬────┘             │
    │       │                │                │                   │
    │       │           ┌────▼────┐           │                   │
    │       └──────────►│   ISE   │◄──────────┘                   │
    │                   │ (AuthN) │                               │
    │                   └────┬────┘                               │
    │                        │                                    │
    │                   ┌────▼────┐                               │
    │                   │   AD    │                               │
    │                   │  LDAP   │                               │
    │                   └─────────┘                               │
    │                                                             │
    │  ┌─────────┐      ┌─────────┐      ┌─────────┐             │
    │  │  Voice  │─────►│  CUCM   │─────►│  NTP    │             │
    │  │         │      │         │      │         │             │
    │  └─────────┘      └─────────┘      └─────────┘             │
    │                                                             │
    └─────────────────────────────────────────────────────────────┘

Critical Dependencies

Application Depends On Impact if Unavailable Mitigation
All Apps DNS (Infoblox) Complete outage Local DNS cache
All Apps Active Directory Authentication failure Cached credentials
SAP Oracle Database SAP unavailable DB HA cluster
Voice CUCM No call control Survivable Gateway
Voice NTP Call timing issues Multiple NTP sources
Email Exchange Online Email outage O365 SLA (99.9%)

1.3.9 Application Requirements Summary

Summary by Category

Category Applications Bandwidth Latency Priority
Real-Time Voice, Video 25% <100 ms Highest
Business Critical SAP, DB, Banking 40% <150 ms High
Cloud/SaaS O365, SFDC, SNow 20% <200 ms Medium
Best Effort Web, File 15% <500 ms Low

Key Recommendations for SD-WAN Design

  1. Voice/Video: Enable FEC and packet duplication for inter-region paths
  2. SAP: Configure dedicated AAR SLA class with <150ms threshold
  3. Database Replication: Use MPLS-only for synchronous replication
  4. Cloud SaaS: Enable Cloud OnRamp with DIA at branches
  5. General: Implement NBAR2 for deep application recognition

References

Document Description
Cisco SD-WAN AAR Design Guide Application-Aware Routing
Cisco QoS Design Guide QoS best practices
SAP Network Requirements SAP Performance Note
Microsoft 365 Network Connectivity O365 requirements

Document Version: 1.0 Last Updated: December 2025 Classification: Internal Use Only Abhavtech.com - SD-WAN Documentation