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MEGSM-155SB-I Multi-service SDH transmission unit


MEGSM-155SB-I is the STM-1 level multi-service Synchronous Digital Hierarchy (SDH) transmission unit compatible with ITU-T standard. It is designed as a modular system with two 155.52Mb/s optical interfaces to provide an ultra-compact, cost-effective and flexible multi-service platform. With optional cards such as E1 card, V35 card, Ethernet card and Engineering Order Wire card, it is easy to meet userís various requirements.
It provides fully cross connectivity between all tributaries, and can be used as Terminal Multiplexer
(TM) or an Add-Drop-Multiplexer (ADM) to build point-to-point, ring and chain transmission network.



  • 1U height, 19 Inch width standard ,1 main board with 3 service card slots

Service interface

  • 2xSTM-1 optical interface, SFP optical module (LC connector)
  • Maximum 16 E1 interfaces compliant with ITU-T G.703 (8 per card), optional unbalanced/ balance interface
  • Maximum 4 10/100BaseT Ethernet electric interface(4 per card)
  • Maximum 6 V.35 interfaces (2 per card)

System interface

  • Ethernet management interface and RS232 management interface (RJ45)
  • External management interface/ external synchronization interface (RJ45)
  • RS232 user channel interface (RJ45)
  • Engineering Order Wire (EOW) interface(RJ11)
  • UALM and DALM output interface(DB9)

Timing mode

  • STM-1 line timing (T1)
  • Any tributary from 1-16 E1 tributary timing (T2)
  • External timing source 2048kHz / 2048Kbit/s(T3/T4)
  • ITU-T G.813 internal oscillator
  • The timing source can be auto-switched according to SSM or operator settings

Ethernet functionality

  • Generic Framing Procedure GFP-F compliant with ITU-T G.7041
  • VCAT compliant with ITU-T G.707 and LCAS compliant with ITU-T G.7042
  • Ethernet flow control on WAN port and LAN port
  • Frame Length(maximum):1536 bytes
  • Auto negotiation of LAN port1+1 protection and Automatic Protect Switch (APS) with the recovering time less than 50ms
  • Supports Remote power Down Detection (RPD) and Auto Laser Shutdown (ALS)
  • Supports embedded BERT and various loop back for troubleshooting
  • Supports firmware download locally without disturbance of existing traffic NE management
  • Supports NE management based on CLI command via RS232 interface or TELNET
  • Supports Network management based on PC via a unified platform

2 hot-spare power cards, both 220V AC and -48VDC available, power consumption less than 15W

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