System Requirements Specification (SRS)
Project: Layer 2 Data Center Extender (L2 DCE)
Version: 1.0
Date: 29/04/2025
Author: Mesut Bayrak
1. Introduction
1.1 Purpose
Describe the purpose of the L2 DCE system (e.g., extend VLANs across data centers with low latency).
1.2 Scope
Define what the L2 DCE will and will not do.
1.3 Definitions, Acronyms, and Abbreviations
- L2 DCE – Layer 2 Data Center Extender
- VXLAN – Virtual Extensible LAN
- DC – Data Center
- BGP EVPN – Border Gateway Protocol Ethernet VPN
- MAC – Media Access Control
1.4 References
List applicable RFCs, whitepapers, standards.
1.5 Overview
Brief description of document structure.
2. Overall Description
2.1 Product Perspective
Describe how L2 DCE fits into the current system (optional: diagram).
2.2 Product Functions
- Extend Layer 2 VLANs transparently.
- Support dynamic MAC learning.
- Ensure loop prevention.
- Provide high availability and low latency.
2.3 User Characteristics
- Users are network engineers familiar with Layer 2/3 concepts.
2.4 Constraints
- Jumbo frame support required.
- Latency and failover constraints.
2.5 Assumptions and Dependencies
- MPLS/IP backbone in place.
- Network hardware supports VXLAN, EVPN, ECMP.
3. Specific Requirements
3.1 Functional Requirements
| ID | Requirement | Description |
|---|---|---|
| FR-1 | VLAN Extension | Extend VLANs 1–4094. |
| FR-2 | MAC Learning | Dynamic MAC learning support. |
| FR-3 | Control Plane | Use BGP EVPN or similar. |
| FR-4 | Failover | Failover within 1s. |
| FR-5 | MTU Handling | Minimum MTU 9100 bytes. |
| FR-6 | Loop Prevention | No Layer 2 loops without relying on STP. |
3.2 Non-Functional Requirements
| ID | Requirement | Description |
|---|---|---|
| NFR-1 | Availability | 99.99% uptime. |
| NFR-2 | Scalability | Support 10,000+ MAC addresses. |
| NFR-3 | Performance | Latency increase < 2ms one-way. |
| NFR-4 | Security | MAC filtering, ARP inspection. |
| NFR-5 | Manageability | SNMP, Netconf, RESTCONF integration. |
4. Interface Requirements
4.1 Hardware Interfaces
- Ethernet interfaces (1G, 10G, 25G, 40G, 100G).
- VXLAN Tunnel Endpoints (VTEPs).
4.2 Software Interfaces
- Standard Linux network stack compatibility.
- API access (gRPC, REST).
4.3 Communication Interfaces
- VXLAN over UDP.
- MP-BGP EVPN over TCP (Port 179).
5. Performance Requirements
- Max bandwidth: [e.g., 40 Gbps per VTEP].
- Max link utilization: 80%.
- Failover convergence time: < 1 second.
6. Security Requirements
- Optional IPsec/MACsec encryption.
- Anti-spoofing: Source MAC/IP validation.
- Role-Based Access Control (RBAC) for management.
7. Other Requirements
- Compliance with security standards (e.g., ISO 27001).
- Appliance power limits (e.g., <300W).
8. Appendix
- Network diagrams.
- Failover flowcharts.
- Supported hardware/software matrix.