The GSN node - a design example
User Eqm. SIM GSM Reference model (simplified) TE MT ME Um Radio Access NW BTS BTS BSS Abis BSC A Gb MSC MSC E G MSC MSC VLR VLR F EIR EIR Gf SGSN SGSN Gn Gr Core NW SCF SCF D C HLR HLR SMS- SMS- IWMSC IWMSC SMS- SMS- GMSC GMSC H Gn, Gp GMSC GMSC GGSN GGSN AUC AUC SC SC Gi Co-operating Networks ISDN PSTN PSPDN CSPDN PDN: - Intranet - Extranet - Internet - X.25 SGSN SGSN Note: Not all interfaces shown and named
Basic hardware characteristics High performance with multi-processor environment and loadsharing. High availability with fault-tolerant hardware platform (no single-point-of-failure). Short time-to-market with sourced boards according to industrial standards (PMC, CPCI). High serviceability with hot swap and hot upgrade/downgrade. High scaleability, both up/downsizing. Standard Ericsson builing practice (BYB 501). Fulfills telecom national standards.
Crane Backplane
PEB
The Board Family PEB - Power & Ethernet switch Board GPB - General Purpose Board Equipped with Sparc processor and harddisk IBxx - Interface Boards All IBxx boards contains 1 Power PC engine processor 1 Power PC processor with accelerator In addition each individual is equipped with the following: IBE1 : 2 or 4 E1 ports IBT1 : 2 or 4 T1 ports IBAE : 1 or 2 ATM Electrical ports IBAM : 1 or 2 ATM optical Multi-mode ports IBAS : 1 or 2 ATM optical Single-mode ports IBEN : 1 or 2 Ethernet 10BaseT/100BaseTx ports
GPB
IBE1
Redundancy support & availability Hardware redundancy: Hot insertion & removal Backplane redundancy No single points of failure Software upgrade during operation Automatic board level failover Repair during operation
Software environment Erlang OTP DPE Solaris Sparc O&M Application HW SS7 DPE VxWorks PowerPC Router
Distributed Programming Environment Middleware = implemented design rules! Capsule concept allows multiple languages Location independent message passing allows (re-)balancing of load over processors Equipment Management detects added/removed hardware, triggers actions Software Management manages multiple releases on the same node
Functionality distribution Traffic control functions GPB GPB Node control functions BSS E1/T1 IBE1 PEB Ethernet switch (Redundant) IBAM IBEN ATM155 or similar Packet flow IBE1
The Connection Broker (next level of middleware) Runtime Environment TC-application components components Development Environment IIOP TC-application ORB Orber(OTP) RD-application SW device WO Application Adapter Logical Switch System Management payload WO Services Connection Broker Kernel db mnesia Core/OTP Resource mng. RD-application SW Device Drivers SW device streams SW device streams UML Rational Rose IDL Erlang/C/JAVA Stubs
Packet Exchange Manager (PXM) PXM = PC/workstation + browser HTML pages Java Applets Web Browser OrbixWeb GSN node HTTP ESI OTP httpd IIOP OTP Orber Dynamic HTML Generator CORBA Service Objects RMI Managed Resource Layer (MRL)
Key characteristics, summary Multiple processor system for scalable capacity Scalable robustness - none, 1+1, n+1 High degree of sourced equipment and software Meets both telecom and datacom requirements Support for C and Erlang O&M based on IIOP, HTTP and Java applets
Challenges Crossing the language boundary => performance penalty => restrictions on design Advanced load sharing mechanisms require more advanced debugging tools High performance nodes require higher performance load generators Zero downtime => combinatorial explosion of configuration combinations => testing strategy complex problem