BCM88483 · Deep buffer · G.8273.2 Class C · 400G ZR ready

Broadcom Qumran 2A Qumran 2A Routers Deep-buffer SP edge with timing. 25/100/400G in 1RU.

Two open-hardware short-depth 1RU routers qualified on OcNOS-SP: Edgecore AS7535-28XB and UfiSpace S9510-28DC. SP metro edge silicon with deep buffers, hardware PTP/SyncE timing, and 400G QSFP-DD uplinks that take ZR and ZR+ coherent optics.

01The Routers 02Inside the Silicon 03Q-Family Map 04OcNOS-SP
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800Gbps
Switch Capacity
2×400G
QSFP-DD ZR Ready
1588v2
Hardware PTP + SyncE
2SKUs
OcNOS-SP Qualified
1RU
Short-depth 300mm
01
The Routers

Two short-depth 1RU sibling routers. Both on OcNOS-SP.

Both platforms share the same architectural class (24×25G + 2×100G + 2×400G on Broadcom Qumran 2A), but come from different ODMs. Both ship with ONIE pre-loaded and run the same OcNOS-SP carrier-grade NOS. Choose based on your procurement needs and which vendor relationship suits your access network. Each card links to the full vendor datasheet (PDF, hosted locally).

Edgecore· AS series
SP edge · deep-buffer aggregation

AS7535-28XB

Qualified on OcNOS-SP · ONIE pre-loaded
Ports
24 × 25G SFP28 + 2 × 100G QSFP28 + 2 × 400G QSFP-DDBreakout: QSFP-DD ports run 50/100/200/400 GbE
Form
1RU · short-depth 300 mm
Power
164 W typical, 383.6 W max · redundant AC or 48 VDCTiming: IEEE 1588v2 PTP · SyncE G.8262
CPU
Intel Xeon D-1539 8-core · 2 × 8 GB ECC RAM
▌ Pick this when

Tier-2/3 SP metro edge for networks with IEEE 1588v2 timing requirements, such as mobile backhaul and FTTH aggregation. Deep buffer and 2 × 400G QSFP-DD uplinks connect to the metro core.

Edgecore AS7535-28XB datasheet PDF
UfiSpace· S9510 series
SP edge · deep-buffer aggregation

S9510-28DC

Qualified on OcNOS-SP · ONIE pre-loaded
Ports
24 × 25G SFP28 + 2 × 100G QSFP28 + 2 × 400G QSFP-DDBreakout: QSFP-DD ports run 100/400 GbE with FlexE
Form
1RU · short-depth 302 mm
Power
369 W max · 1+1 redundant AC or DCTiming: Class C PTP · SyncE G.8262
CPU
Intel · 8 or 16 GB RAM
▌ Pick this when

Same port mix as AS7535-28XB (24 × 25G, 2 × 100G, 2 × 400G) on Qumran 2A. Pick by ODM relationship, RMA logistics, or where UfiSpace platforms already run in the access network.

UfiSpace S9510-28DC datasheet PDF

· How Qumran 2A fits in the Q-family

Q2U vs Q2AQ2U (BCM88284) is the compact CSR: fewer ports, no 400G, lower power. Q2A is the deeper-buffer aggregation/edge step up.
Q2A vs Q2CQ2C has more 100G/400G ports for larger metro hubs. Q2A is sized for short-depth edge cabinets where 24×25G + 2×100G + 2×400G is the right port mix.
Q2A vs J2C+J2C+ is the carrier-core class: up to 14.4 Tbps with external TCAM for large route tables. Use Q2A in front of it as the edge.
Timing-first deploymentsBoth Q2A platforms support hardware IEEE 1588v2 PTP and SyncE, with the ITU-T G.8275.1 profile for mobile backhaul and midhaul. The S9510-28DC datasheet lists Class C timing accuracy.
02
Inside the Silicon

Qumran 2A: deep-buffer access aggregation at 800 Gbps.

The BCM88483 Qumran 2A is Broadcom's deep-buffer SP edge ASIC: 800 Gbps switching capacity tuned for the access aggregation role rather than DC east-west traffic. The port mix on the qualified platforms (24 × 25G + 2 × 100G + 2 × 400G) reflects that role: many access-side downlinks, a handful of high-capacity uplinks. The 400G ports are QSFP-DD.

Two things distinguish Q2A from a DC switch chip. Hardware-assisted PTP for mobile backhaul timing. Deep buffer architecture sized for asymmetric N:1 fan-in from the access side.

Sources: Broadcom BCM88483 product page and the linked vendor datasheets.

SeriesStrataDNX BufferDeep TimingG.8273.2 Class C · SyncE Optics400G ZR ready

· Port mix · 800 Gbps shaped for the edge

Access · 25G24 × SFP28
Mid · 100G2 × QSFP28
Uplink · 400G2 × QSFP-DD (ZR)
BCM88483 die800 Gbps
Asymmetric port mix: many access-side downlinks, two 400G uplinks. Hardware PTP and SyncE.

Why Q2A is the SP edge chip, not a smaller DC switch.

Four design choices fit Q2A to SP roles.

Deep buffer, asymmetric.

Buffers sized for N:1 fan-in patterns from the access side: long-lived TCP flows, subscriber churn, oversubscription bursts. Not the same shape as a DC switch shared-buffer pool. Carrier-grade SLAs hold.

Deep buffer · asymmetric

Hardware PTP Class C.

IEEE 1588v2 timestamping in hardware. G.8273.2 boundary clock, with Class C timing accuracy listed for the S9510-28DC. G.8275.1 and G.8275.2 profiles for mobile backhaul and midhaul.

G.8273.2 · Class C

SyncE G.8262.

Frequency synchronization alongside PTP, with ESMC SSM messaging. PTP provides phase synchronization and SyncE provides frequency synchronization, as 5G timing budgets require.

G.8262 · ESMC

QSFP-DD coherent-ready.

On both platforms, the two 400G QSFP-DD ports support 400G ZR and ZR+ pluggable coherent optics with OcNOS-SP PLUS. The same box handles access aggregation and metro DCI uplink.

400G ZR · ZR+
03
The Q-Family Map

Four chips, four roles. Pick by the edge or the core you build.

Broadcom's StrataDNX (Qumran/Jericho) family covers SP roles from compact CSR to carrier core. Q2A is the deep-buffer edge with timing, sized for metro and tier-2 aggregation.

Compact SP CSR.

Smaller box, ~360 Gbps capacity. Cell-site gateway, DSLAM aggregation, Tier-3 SP edge. PTP timing, no 400G. Q2U page →

~360 Gbps · 1RU QUMRAN 2U · BCM88284

SP edge with deep buffer + 400G ZR.

You are here. 800 Gbps with 400G ZR coherent in QSFP-DD. PTP/SyncE. Sweet spot: metro edge / tier-2 aggregation with timing.

800 Gbps · 400G ZR ready QUMRAN 2A · BCM88483

Larger metro hub.

Higher 100G/400G port density than Q2A. Use when access-side density is the constraint.

2.4 Tbps QUMRAN 2C

Carrier-core router.

Up to 14.4 Tbps, with external TCAM for large route tables. Sit Q2A in front of it as the edge. J2C+ page →

14.4 Tbps · 2RU JERICHO 2C+
04
What OcNOS-SP Ships

OcNOS-SP with PTP, SyncE and SR-MPLS.

OcNOS-SP provides Q2A's full SP feature set (Layer 3 routing, MPLS service plane, IEEE 1588v2 timing, streaming telemetry and NETCONF automation) through one configuration model. See the OcNOS feature matrix for the full list.

Segment Routing-MPLS native, RSVP-TE for legacy.

Full SR-MPLS with TI-LFA fast reroute, Flex-Algorithm constraint paths, and BGP-LU for inter-AS labelled unicast. RSVP-TE remains available for legacy interoperability. EVPN-MPLS overlays provide multi-tenant L2VPN/L3VPN services without proprietary glue.

G.8273.2 Class C + SyncE G.8262.

Full G.8275.1 and G.8275.2 mobile profiles. Boundary clock and transparent clock modes. SSM/ESMC.

iPo-DWDM in the metro.

OIF/CMIS-managed coherent optics plug directly into QSFP-DD ports, eliminating the need for a transponder shelf.

400G ZR Coherent

BGP · IS-IS · OSPF · L3VPN.

BGP, IS-IS and OSPF. Full L3VPN service plane with VPNv4/v6.

The OcNOS feature matrix, per platform.

Every SP feature category: routing, MPLS service plane, EVPN, timing, automation, security. Verifiable per-platform on the public matrix.

SR-MPLS / TI-LFA BGP-LU EVPN-MPLS L3VPN VPNv4/v6 PTP G.8275.1 SyncE G.8262 400G ZR / ZR+ Telemetry / NETCONF ZTP
Day-0 to Day-2

ZTP, streaming telemetry, NETCONF and YANG.

Bring up the AS7535-28XB or S9510-28DC in the rack with zero-touch provisioning, and stream telemetry to your observability stack.

ZTP IPv4/IPv6 Streaming telemetry NETCONF OpenConfig YANG Ansible

Three SP profiles. One edge silicon for all three.

Q2A's combination of deep buffer, timing, and 400G ZR coherent puts it in three different conversations: mobile aggregation, metro DCI, and carrier broadband edge.

Cell-site backhaul into the metro core.

"Our 5G backhaul timing budget is tight. We need Class C PTP and SyncE, and we don't want to deploy a separate timing appliance."

Q2A platforms support hardware IEEE 1588v2 PTP and SyncE G.8262, with Class C timing accuracy listed for the S9510-28DC. The G.8275.1 profile is available out of the box. The platforms aggregate 24 × 25G cell-site uplinks and connect to the metro core over 2 × 100G + 2 × 400G.

SP · 5G Aggregation

Transponder-free metro DCI without a shelf.

"We have two regional aggregation hubs 80 km apart. The optical group wants to retire the transponder shelf. We need 400G between them and IP-layer visibility."

On both platforms, the 2 × 400G QSFP-DD ports take 400G ZR and ZR+ pluggable coherent optics with OcNOS-SP PLUS. EVPN-MPLS inter-DC for tenant extension. Both hubs run the same OcNOS-SP software.

SP · iPo-DWDM

FTTH / FTTx edge aggregation.

"Our access network is GPON/XGS-PON to subscribers, aggregated through OLTs. The metro edge router has to absorb burst traffic from N:1 fan-in without dropping, and run BGP-LU into the core."

Deep buffer absorbs asymmetric N:1 fan-in bursts. A 1/2/3-level queuing hierarchy shapes traffic per queue and per port. SR-MPLS with BGP-LU connects to the core, and EVPN-MPLS supports L2/L3VPN services. OcNOS-SP runs on every edge box.

SP · FTTH Edge
Full Feature Matrix SP Networks Solution SR-MPLS Deep-Dive Hardware Compatibility List

Questions SP architects ask

Two open-hardware 1RU short-depth platforms: Edgecore AS7535-28XB and UfiSpace S9510-28DC. Both platforms run Broadcom Qumran 2A silicon, ship with ONIE pre-loaded, and run the same OcNOS-SP software. They are sized for SP metro edge and aggregation roles where IEEE 1588v2 timing, deep buffer, and 400G ZR coherent optics matter together.
SP edge boxes carry mixed traffic: long-lived flows from the access network, bursts during subscriber churn, and oversubscribed N:1 fan-in. Without deep buffer, transient congestion drops packets and triggers TCP retransmissions. Q2A's deep buffer absorbs the bursts. Combined with a 1/2/3-level queuing hierarchy, it helps maintain customer SLAs under realistic load.
Hardware-assisted IEEE 1588v2 PTP and SyncE (ITU-T G.8262, ESMC G.8264). OcNOS-SP runs grandmaster, boundary clock and transparent clock modes with the ITU-T G.8275.1 and G.8275.2 telecom profiles. The S9510-28DC datasheet lists Class C timing accuracy. Built for mobile backhaul and midhaul timing.
Yes. Both platforms have 2 × 400G QSFP-DD ports that take 400G ZR and ZR+ pluggable coherent optics with OcNOS-SP PLUS. Plug the coherent module directly into the router without a transponder shelf.
Q2U (BCM88284) is a compact CSR with fewer ports, no 400G, and lower power consumption. Q2C is the deeper-radix sibling: more 100G/400G ports for larger aggregation. J2C+ is the carrier-core class: up to 14.4 Tbps with external TCAM for large route tables. Q2A sits in the middle: deep-buffer edge with timing, sized for metro and tier-2 aggregation.
A full carrier-grade Layer 3 stack: BGP (with BGP-LU), IS-IS, OSPFv2/v3, SR-MPLS with TI-LFA, RSVP-TE for legacy interop, LDP, L2VPN/L3VPN MPLS services, EVPN-MPLS for multi-tenant L2/L3. On the timing side: PTP and SyncE, with full G.8275.1/G.8275.2 profiles. Standard automation includes streaming telemetry, NETCONF, OpenConfig YANG, and ZTP. See the OcNOS feature matrix for the full list.
For Tier-1 carrier core, use J2C+ for its much higher capacity and table sizes. For pure DC fabric, use Trident or Tomahawk for their DC feature set. For sub-100G access aggregation, Q2U is a better fit at lower cost. For 800G uplinks, no OcNOS-SP platform has 800G ports; that is TH5 territory. Q2A fits SP metro edge roles that need timing and 400G ZR readiness.

Designing a deep-buffer SP edge with 400G ZR ready?

30-minute architecture session with an OcNOS network architect. Bring your timing requirements, port-mix expectations, and metro-DCI plans, and leave with a sized BoM around AS7535-28XB / S9510-28DC.

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