Fanless Cell Site Routers for 5G Backhaul: OcNOS in Remote and Rugged Environments

Not every cell site is located in a climate-controlled equipment room. 5G deployments increasingly push network equipment into outdoor cabinets, street-level enclosures, rooftop installations, and remote tower sites where dust, temperature extremes, and lack of power for active cooling make traditional router hardware unsuitable.

OcNOS supports a range of fanless Cell Site Router (CSR) platforms specifically designed for these environments, delivering full 5G backhaul capabilities — SR-MPLS transport, EVPN services, and IEEE 1588v2 PTP timing — without a single spinning fan.

Why 5G Backhaul Needs Purpose-Built CSR Hardware

A 5G cell site gateway must satisfy requirements that go well beyond basic IP routing:

• Timing accuracy — 5G NR (New Radio) requires phase synchronization accurate to ±1.5μs (microseconds). This demands IEEE 1588v2 PTP with hardware timestamping support, not software-only PTP.
• Rugged operation — operating temperature range typically −40°C to +70°C for outdoor equipment; fanless passive cooling eliminates the most common point of failure in harsh environments.
• SR-MPLS backhaul — 5G transport architectures use SR-MPLS for deterministic path control and fast reroute; the CSR must participate as an IS-IS SR node with full TI-LFA support.
• Small form factor — street cabinets and outdoor enclosures have limited rack space; compact 1U or sub-1U platforms are required.

OcNOS Fanless CSR Platforms

OcNOS CSR Configuration for 5G Backhaul

! OcNOS CSR -- 5G backhaul: SR-MPLS + PTP configuration
!
configure terminal
!
! IS-IS SR for backhaul transport
interface lo
  ip address 10.5.0.50/32 secondary
  ip router isis BACKHAUL
  prefix-sid index 50
  exit
!
interface eth-0-1
  no shutdown
  ip address 192.168.50.1/30
  label-switching
  ip router isis BACKHAUL
  isis network point-to-point
  isis metric 10
  synce
  exit
!
router isis BACKHAUL
  net 49.0002.0000.0000.0050.00
  is-type level-2-only
  metric-style wide
  mpls traffic-eng router-id 10.5.0.50
  mpls traffic-eng level-2
  segment-routing mpls
  fast-reroute ti-lfa level-2 proto ipv4
  exit
!
! IEEE 1588v2 PTP for 5G timing (ITU-T G.8275.1 profile)
ptp clock 0 profile g8275.1
!
commit
exit
!
! Verify:
show clns neighbors
show isis segment-routing state
show ptp clock 0
show synce details

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