Overview
GR-303 is a standard interface for Integrated Digital Loop Carrier (IDLC) systems that consists of an Integrated Digital Terminal (IDT)
located in the Local Digital Switch (LDS) and a Remote Digital Terminal (RDT) located at the customer premises. RDT's main function is to multiplex
traffic from a number of subscriber lines onto a high-speed transmission facility (SONET, DS3, or DS1s) for transport to/from the central office.
GR-303 uses three message-based signaling channels namely, Timeslot Management Channels (TMC), Common Signaling Channels(CSC),
and Embedded Operation Channels (EOC). TMCs are used for timeslot allocation and time-slot allocation and call processing messages
between the RDT and the LDS. The higher layer protocols used with this channel are LAPD subset for layer 2, and a subset of Q.931 for
layer 3. CSCs are used instead of TMC for clean out-of-band signaling implementation. CSC messages can handle both call supervision and
time slot assignment. EOCs are use for remote management operations such as maintenance and alarm surveillance.
GL's GR303 Analyzer offers testing for all aspects of GR-303 systems: monitoring T1 Line, monitoring the TMC/CSC control channel,
monitoring EOC channel, viewing robbed ABCD signaling and dialed digits, listening to voice channels, and thorough tests for the physical
layer. The GR-303 option troubleshoots signaling problems between the switch and remote terminal: to determine call status, monitor for
any dropped calls, detect any abnormal conditions, and identify when service was unavailable. With these extensive GR-303 protocol
analysis tools, you can analyze call setup and monitor communications between network elements and resolve problems as new
network challenges emerge.
GL Communications supports the following types of GR-303 analyzers:
- Real-time GR-303 Analyzer (Pre-requisites: GL's field proven E1 or T1 internal cards or USB Laptop E1 or T1 external units, required
licenses and Windows 2000/XP Operating System)
- Remote/Offline GR-303 Analyzers (Pre-requisites: Hardware Dongle, and Windows 2000/XP Operating System)
GR-303 Analyzer Main Features:
- Decode Embedded Operational Channel (EOC) messages for diagnosing operations, administration, maintenance and provisioning
(OAM & P).
- Provide real-time call-setup analysis of the Timeslot Management Channel (TMC) and Common Signaling Channel (CSC).
- Monitor both TMC/CSC and EOC simultaneously to correlate call-setup and OAM&P
- Provides Summary View, Detail View, Hex dump, Statistics, and Call-trace views.
- Summary view displays the SAPI, TEI, C/R, Message type (for TMC/CSC) and ROSE APDU (for EOC).
- Detailed view displays decodes of user-selected frames.
- Hex dump view displays raw frame data as hexadecimal and ASCII octet dump.
- Statistics view displays statistics based on frame count, byte count, frames/sec, bytes/sec etc for the entire captured data.
- Call trace view displays call statistics such as number of active/completed calls, durations of the completed calls, Device No, CRV and
Timeslot.
- Capability to export summary as well as detail information to an ASCII file for subsequent import into a database or spreadsheet.
- Supports filtering and search features based on Call Reference Value (CRV) and many other message types.
- Remote monitoring capability using GL's Network Surveillance System.
Additional features supported by real-time/remote GR-303 analyzer are:
- Streams can be captured on the selected time slots (contiguous or non-contiguous), sub-channels or full bandwidth.
Frames may also be contained in either one, n x 64 kbps, or n x 56 kbps data channels. The following variations are accommodated
in the software: inverted or non-inverted data, byte reversal or non-reversal.
- The following variations are accommodated in the software: inverted or non-inverted data, byte reversal or non-reversal.
- Supports real-time filtering based on the frame length value.
- Multiple streams of GR303 traffic on various T1/E1 channels can be simultaneously decoded with different GUI instances
- Multiple remote clients may access a single T1/E1 server, which enables monitoring two or more cards instantaneously.
(For Remote Analyzers only)
- Captured frames can later be used for traffic simulation using HDLC Transmit/Playback application
Additional features supported by Offline GR-303 Analyzer:
- Trace files for analysis can be loaded through simple command-line arguments
- Multiple trace files can be loaded simultaneously with different GUI instances for offline analysis
Supported Protocols
- GR-303 LAPD:Telcordia, Telcordia GR-303-IMD (formerly TR-TSY-000303)
- Series X (Data networks and open system communication):X.208, X.209, X.219, X.229, X.710, X.711
- TMC & CSC: GR-303-CORE Issue 3 December 1999 and GR-303-CORE Issue 3 December 1999
- EOC:GR-303-CORE Issue 3 December 1999
Summary, Detail and Hexdump View
The GR-303 analyzer application is invoked from the main menu of GL's T1/E1 Analyzer for real-time analyzer. The remote/offline GR-303
analyzer is invoked from the installation directory of the Remote GR-303 Analyzer. The analyzer displays summary, detail and hex dump view
in different panes. The summary pane displays Frame Number, Time, Length, Error, C/R, SAPI, CTL, P/F, FUNC, CRV message type
(for TMC/CSC) and ROSE APDU (for EOC) and more. To analyze in detail, user can select a frame in summary view to analyze and decode in
the detail view. The Hex dump view displays the frame information in HEX and ASCII format.
Summary, Detailed and Hexdump View
Real-time and Off-Line Analysis
Users can capture and analyze GR-303 frames using either real-time or remote analyzers. All or filtered traffic can be recorded into a
trace file. The recorded trace file can then be analyzed offline and exported to ASCII file, or printed. Real-time capturing requires user to
specify timeslots, bit inversion, octet bit reversion, user/network side, and data transmission rate. Recorded trace file can be played back
on T1/E1 using the file HDLC Playback option.
Screen Shot of Real-time and Offline Analysis
Filtering and Search
Users can record all or filtered traffic into a trace file. Filtering and search capability adds a powerful dimension to the GR-303
analyzer. This feature can isolate required frames from captured frames in real-time/remote/offline. Users can specify custom values
for frame length to filter frames during real-time capture. The frames can also be filtered after completion of capture according to
Frame Number, Time, Length, Error, C/R, SAPI, CTL, P/F, FUNC, CRV and more. Similarly, Search capability helps user to search for a
particular frame based on specific search criteria.
Screen Shot of Filtering and Search
Call Trace and Statistics View
Call trace defining important call specific parameters like Call ID, Call Status, Call duration, CRV, Release Cause etc are calculated for
LAPD layer. Call traces can also be logically grouped with each group comprised of unidirectional (either 'Forward' or 'Backward') data links.
Statistics is an important feature available in GR-303 analyzer and can be obtained for all frames both in real-time as well as offline mode.
Numerous statistics can be obtained to study the performance and trend in the GR-303 network and it is based on protocol fields and
different parameters e.g. Use Type (Key/Total/Field), Statistic type (Frame/Byte count, Frames/Sec) etc.
Screen Shot of Statistics and Call Trace Window
Enhanced Trace Saving Options
Users can control the captured trace files by saving the trace using different conventions such as trace files with user-defined prefixes,
trace file with date-time prefixes, and slider control to indicate the total number of files, file size, frame count, or time limit. This feature also
allows the captured frames to be saved into a trace file based on the filtering criteria set using display filter feature.
Screen Shot of Enhanced Trace Saving Options Window
Save/Load All Configuration Settings
Protocol Configuration window provides a consolidated interface for all the important settings required in the analyzer. This includes
various options such as protocol selection, startup options, stream/interface selection, filter/search criteria and so on. All the configuration
settings done in any of these options can be saved to a file, loaded from a configuration file, or user may just revert to the default values
using the default option.
Screen Shot of Save/Load All Configuration Setting Window
Bridge and Monitor Connections
Buyer's Guide:
Please Note: The XX in the Item No. refers to the hardware platform, listed at the bottom of the Buyer's Guide,
which the software will be running on. Therefore, XX can either be DPT, DPE, PCT, PCE, HDT, HDE, DLT, DLE or UTE depending
upon the hardware.
Specifications are subject to change without notice.
Back to Protocol Analysis Index Page
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