1. Telscale SS7 card
Part 1: long intro
● SS7, Sigtran and TDM
● What is it? G.704 structure
● Who are competitors?
● How long TDM will survive?
Part 2: Telscale SS7 card
● Architecture
● Use cases
● Software structure
● Current state & Goals

2. Telscale SS7 card
jSS7 and Telscale Card
CAMEL MAP
ISUP TCAP
SCCP →a card to convert SS7 into Sigtran
(M3UA, M2UA, M2PA)
M3UA MTP3 → support media (MGCP+G.711)
SCTP TCP MTP2 → G.703 to SIP gateway
→ G.703 probe
Ethernet HW

3. Telscale SS7 card
E1, T1 etc
● G.703 — pulse shaping, masks
● Bipolar coding with clock recovery (HDB-3 for E1)
● Sequence of bits
TS31 TS0 TS0 TS0 TS0 TS0 TS0 TS0 TS0 TS1 TS1
bit 7 bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 0 bit 1
● 32 channels (time slots), 8 bits each
● Time slot 0: G.704. Dedicated content
● A time slot is a 64k channel: SS7 link, G.711 voice or whatever
● Quality monitoring: PBV (code errors) + CRC-4 (timeslot 0)
.. and why do they call it G.703?

4. Telscale SS7 card
Cards at the Market
● Dialogic
– sophisticated card with CPU onboard
– voice and signaling onboard
– OS driver, API
● Digium (Asterisk)
– low cost card w/o inteligence
– OS driver, interfaces timeslots to host CPU
● Telscale Card
– NO drivers:
stand-alone system with Ethernet interfacing
– DSP running uClinux:
DSP interfaces(SPORT) + power of linux

5. Telscale SS7 card
Is there a Market?
● GSM world (various SS7 apps with or w/o voice)
– initial GSM specs; available everywhere
– too much was invested
● Interfacing existing PBXs (ISDN ↔ SIP)
.. how long G.703 will survive?
.. how long will SS7 live?

6. Telscale SS7 card
Architecture
DSP Core
– running uClinux
– 2 Ethernet
E1/T1
line FPGA
interfacing
Additional – E1/T1 interfacing RAM SPI Par.
E1/T1 – SS7 MTP2(HDLC) 128M flash flash
receivers
FPGA
conf.memory

7. Telscale SS7 card
Use Cases
→ PCM terminal
● Set of SS7 terminals
● SS7 terminals + optional Voice
● ISDN ↔ SIP
→ SS7 probe for various apps

8. Telscale SS7 card
Software Structure
Part 1
An embedded system
with FPGA and linux
Flexible Schematics that
→ must be configured (from SPI flash)
to “build” a “hardware”
→ DSP can “reload” a new schematics
(@another offset)
→ SPI content can be changed Linux system that has
→ a flexible boot loader
→ linux + applications

9. Telscale SS7 card
Software Structure
Part 2
→ Various SS7/Sigtran stacks
in parallel
M3UA → SS7 links are distributed
M2UA M2PA
via shared memory
→ “multiplexing” works with
array of time slots,
SS7 links via SHM ea ether
→ processes time slot as
SS7 link
“Multiplexing” → controls time slot via
MGCP (ea media)
→ each driver interfaces
PCM driver PCM driver a PCM line

10. Telscale SS7 card
Current state & Goals
→ deployed already
→ production state, commercially available
Production (now)
→ fixing production cycle and logistics
Optimization (Q4'12) Features(Q1'13)
→ driver re-design (char → MMAP) → M2PA for card
→ moving part of MTP2 to FPGA → M2PA for jSS7
USABILITY
→ user-friendly configuration
FEATURES
→ SCTP Multihoming
→ M2UA/M2PA ?
→ T1 if requested
→ pseudo-interfaces for wireshark
VOICE
→ MGCP+RTP
→ DTMF+ECHO

11. Telscale SS7 card
Questions? Ideas?
Dmitri.Soloviev@telestax.com
http://OpenSigtran.org