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+Specifications
+**************
+
+
+SDN Features
+============
+  - ONOS cluster of all-active N instances affording N-way redundancy and scale, where N = 3 or N = 5.
+  - Unified operations interface (GUI/REST/CLI)
+  - Centralized configuration – all configuration is done on controller instead of each individual switch
+  - Centralized role-based access control (RBAC)
+  - Automatic host (end-point) discovery – attached hosts, access-devices, appliances (PNFs), routers, etc.
+  - based on ARP, DHCP, NDP, etc.
+  - Automatic switch, link and topology discovery and maintenance (keep-alives, failure recovery)
+
+L2 Features
+===========
+Various L2 connectivity and tunneling support
+  - VLAN-based bridging
+
+    - Access, Trunk and Native VLAN support
+  - VLAN cross connect
+
+    - Forward traffic based on outer VLAN id
+    - Forward traffic based on outer and inner VLAN id (QinQ)
+  - Pseudowire
+
+    - L2 tunneling across the L3 fabric
+    - Support tunneling based on double tagged and single tagged traffic
+
+      - Support VLAN translation of outer tag
+
+L3 Features
+===========
+IP connectivity
+  - IPv4 and IPv6 unicast routing (internal use of MPLS Segment Routing)
+  - Subnetting configuration on all non-spine facing leaf ports; no configuration required on any spine port
+  - IPv6 router advertisement
+  - ARP, NDP, IGMP handling
+  - Number of flows in spines greatly simplified by MPLS Segment Routing
+  - Further reduction of per-leaf flows with route optimization logic
+
+DHCP Relay
+==========
+DHCP L3 relay
+  - DHCPv4 and DHCPv6
+  - DHCP server either directly attached to fabric leaves, or indirectly connected via upstream router
+  - DHCP client directly either attached to fabric leaves, or indirectly connected via LDRA
+  - Multiple DHCP servers for HA
+
+vRouter
+=======
+vRouter presents the entire Trellis fabric as a single router (or dual-routers for HA), with disaggregated control/data plane
+  - Uses open-source protocol implementations like Quagga (or FRR)
+  - BGPv4 and BGPv6
+  - Static routes
+  - Route blackholing
+  - ACLs based on port, L2, L3 and L4 headers
+
+Multicast
+=========
+Centralized multicast tree computation, programming and management
+  - Support both IPv4 and IPv6 multicast
+  - Dual-homed multicast sinks for HA
+  - Multiple multicast sources for HA
+
+Troubleshooting & Diagnostics
+=============================
+  - Troubleshooting tool – T3: Trellis Troubleshooting Tool
+  - Diagnostics one-click collection tool `onos-diags`
+
+Topology
+========
+  - Single leaf (ToR) or dual-ToR (dual-homing)
+  - Supports typical leaf-spine topology, 2 to 4 spines, up to 10 leaves
+  - Multi-stage leaf-spine fabric (leaf-spine-spine-leaf)
+  - Can start at the smallest scale (single leaf) and grow horizontally
+
+Resiliency
+==========
+Provides HA in following scenarios
+  - Controller instance failure (requires 3 or 5 node ONOS cluster)
+  - Link failures
+  - Spine failure
+Further HA support in following failure scenarios with dual-homing enabled
+  - Leaf failure
+  - Upstream router failure
+  - Host NIC failure
+
+Scalability
+===========
+  - (in production) Up to 50k routes, 110k flows, 8 Leaf, 2 Spines, with route optimization enabled
+  - (in pre-production) Up to 120k routes, 250k flows, 8 Leaf, 2 Spines, with route optimization enabled
+
+Security
+========
+  - TLS-secured connection between controllers and switches (premium feature)
+  - AAA 802.1x authentication
+  - MACSec (L2 encapsulation)
+
+P4-ready
+========
+  - Support for Stratum, P4Runtime and gNMI and P4 programs
+  - Innovative services enabled by programmable pipeline
+
+    - BNG – PPPoE, anti-spoofing, accounting and more
+    - GTP encap/decap
+
+Overlay Support
+===============
+  Can be used/integrated with 3rd party overlay networks (e.g. OpenStack Neutron, Kubernetes CNI)
+
+Orchestrator Support
+====================
+  Can be integrated with external orchestrator, logging, telemetry and alarm service via REST apis and Kafka events
+
+Controller Server Specs
+=======================
+Recommended (per ONOS instance)
+  - CPU: 32 Cores
+  - RAM: 128GB RAM. 65GB dedicated to ONOS JVM heap (based on 50K routes)
+
+Whitebox Switch Hardware
+========================
+  - Multi-vendor: Edgecore, QCT, Delta, Inventec
+  - Multi-chipset
+
+    - Broadcom Tomahawk, Trident2, Qumran
+    - Barefoot Tofino
+  - 1/10G, 25G, 40G to 100G
+  - Refer to docs.trellisfabric.org/supported-hardware.html for the most up-to-date hardware list
+
+Whitebox Switch Software
+========================
+  - Open source ONL, ONIE and Indigo OF client
+  - (in production) OF-DPA software commercial version – contact Broadcom
+  - (in labs/trials) OF-DPA software community version available from ONF (for switch models based on Trident and Tomahawk, not Qumran)
+  - (in labs/trails) Stratum available from ONF
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