Overview
PoS is a highly scalable layer 2 protocol that uses PPP encapsulation to carry IP packets directly in
SONET/SDH networks. Currently it carries a majority of the Internet traffic because it can make efficient use
of existing SONET infrastructure. PoS uses practically all optical interfaces, and is defined by the Internet
Engineering Task Force (IETF) in the following RFC documents:
- RFC 1661 – The Point-to-Point Protocol (PPP)
- RFC 1662 – PPP in HDLC framing
- RFC 2615 – PPP over SONET / SDH
- SONET is described in BellCore GR-253-core
- SDH is described in ITU G.707
The format and steps below show how IP packets are mapped into SONET / SDH payloads:
- Apply 20 bytes IP header for each IP packet
- PPP packet headers and HDLC framing are applied to each IP Datagram
- Frame check sequences (FCS) and octet stuffing are appended to the IP Datagram
- Idle flags are inserted in between frames (IP Packets)
- Final scrambling of the IP Datagram and synchronous mapping by octet into the SONET/SDH frame
The above procedure is continued for remaining IP Datagrams that make up the IP packet.
PoS packet structure
GL's LightSpeed 1000 analyzer supports PoS, or Packet over SONET / SDH at OC-3/12 and STM-1/4 at full
rates over dual interfaces. Access, capture, analysis, and emulation of PPP and HDLC, all carrying IP traffic in
real-time makes this card useful to many applications including Routing, Deep Packet Inspection, and other
Internet traffic applications. Multiple cards can be installed in a PC making it scalable to monitor or generate
OC-3 or OC-12 traffic on multiple ports. Each port on a card can work independent of others, which extends
analyzer's flexibility as test equipment.
OC-3 / STM-1 OC-12 / STM-4 PoS Analyzer Features
- Capture and analyze Point-to-Point Protocol (PPP) over SONET/SDH as per RFC 2615.
- Supports payload scrambling of polynomial 1+X^43.
- Supports up to16 hardware filter each of 128 bits. All filters are protocol independent providing greater
flexibility. Deep packet inspection becomes easier with support of filter offset feature.
- SONET Statistics supported: Link State, Line Speed, Section LOS, Section LOF, Section BIP (B1), Line AIS,
Line RDI, Line REI (FEBE), Line BIP (B2), Path AIS, Path RDI, Path REI (FEBE), Path BIP (B3).
- Monitoring and configuring of section, line, and path overhead bytes.
- Packet statistics: Tx/Rx Byte Count, Tx/Rx Packet Count, Rx FCS Error Count, Rx Abort Packet Count, Rx
Minimum and Maximum Packet Length Violation Error Count.
- TCP/IP Statistics supported: IP Packets Received, IP Checksum Errors, UDP Packets Received, UDP
Checksum Errors, TCP Packets Received, TCP Checksum Errors, ICMP/IGMP/IGRP Packets Received.
- Multistage loopback - Supports Rx-to-Tx memory loopback, line loopback and diagnostic loopback options.
- Capture unlimited data to file on individual ports, limited only by hard disk size.
- PPP protocol analysis supported on single or multiple ports
- Monitor and configure section, line, and path overhead bytes.
- Captures the traffic to files in raw format.
Alarms and Error Monitoring
The alarm and error monitoring window is provided for each of the OC3/12 port displays the detail status
of the communication with the other end. Error logging capability saves all alarm conditions to a file for later
diagnosis. Hardware LEDs are provided on the card to read line alarms. User-defined hardware LED can be
programmed as demanded.
Conditions monitored include –
- Line errors such as OOF, LOS, LOF, AIS, RDI, and APSBF
- SONET line frequency, power level, FEAC Messages, FCS, Rx / Tx Abort, and MIN / MAX Length
- Line, Path, and Section error counts
PoS Alarms
PoS Port Configuration
PoS Port Configuration allows users to select FCS type, control FCS stripping on Rx and FCS appending on Tx,
and dropping /passing frames with incorrect FCS on Rx.
Rx FCS Bit Count - the receive side will check for 32bits, 16 bits, or none FCS value at the frame end.
Rx FCS Octets Present - allows the receiving side to strip the FCS octets from received PoS frames or
to leave the appended FCS octets as received.
Rx FCS Error Frames - allows to drop the FCS error frames by hardware making them unavailable to
software applications or pass the FCS error frames at the receiving side.
Tx Append FCS – allows to add the FCS octets at the end of every frame at the transmission side.
OC-3 / STM-1 and OC-12 / STM-4 PoS Analyzer Applications
Following applications are supported in OC-3 / STM-1 and OC-12 / STM-4 analyzer –
PoS Tx/Rx Test
This application provides users the option to send the test packets with fixed, random, or variable lengths,
and insert user-defined frame header in the packets transmitted. The statistics displays the transmitted and
received packets, lost packets and receive sequence erred packets. The Rx sequence errors can be categorized
based on Rx error stat length bucket value set.
PoS Tx/Rx Test
PoS BERT
This application permits BER test to run over PPP, IP, or UDP layers.
- User-defined header configuration also supported.
- User-defined traffic rate to the accuracy of 0.001% of total bandwidth.
- Payload configuration to different PRBS patterns or user defined pattern. User defined pattern length can
be 2 to 32 bits in length.
- User-definable pre-sync achieve window, sync loss bits window, and sync loss declare window.
- Supports sequence number insertion, invert payload data, single bit error insertion, and error rate insertion.
- Provides detail statistics, such as Rx/Tx packet count, bit error count, IP and UDP checksum error count.
- Provides throughput details, error and alarm LEDs for easy analysis.
The PoS protocol analysis is used to capture packets over SONET/SDH and provide complete analysis of
the protocol headers. The application supports filtering, statistics, remote connection via TCP/IP and many
more functions.
PoS Protocol Analyzer
For more information, please click here.
PoS Record / Playback
This software allows users to transmit and / or capture packets / cells from file / to a file with GL's
OC3/12 PoS Analyzer. Files of any length can be transmitted and captured continuously (without loss) over
SONET interface. The analyzer can capture (record) the received packets into a file (by Receive Packets to File module).
It can also transmit (playback) already captured DAT file over SONET interface.
These applications are explained in detail below.
Transmit Cells (Packets) from File
This application permits transmission of PoS packets / cells over SONET interface. Users can specify
the transmission limit by selecting different options. The file can be transmitted on the selected port
continuously, for limited number of cells/packets or till the end of file is reached (EOF). Tx bandwidth can
be controlled by specifying the data rate in packets/sec. The GUI displays the statistics of the transmitted
packets (or cells) per second.
Features
- Transmits packets / cells
- Packets can be transmitted either continuously or till the end-of-file (EOF)
- Transmits packets/cells at user configurable rate
- Swap port option to send data on selected ports
- Provides the statistics of the transmitted cells at both line level and payload level
Playback Packets from File
Receive Packets to File
This application permits continuous or limited capture of packets on the SONET interface and saves to a file. Files
of any length can be captured continuously (till user manually stops the capture)) over SONET interface and are limited
only by a hard drive size.
Features
- Captures the received packets and saves into a file
- Packets can be captured continuously or up to a specified size in MB or number of packets
Record Packets to File
Buyer's Guide
| Item No. |
Item Description |
| LTS201 |
OC-3 / STM-1 PoS Monitor, BERT, Tx/Rx Test, RAW |
| LTS301 |
OC-12 / STM-4 PoS Monitor, BERT, Tx/Rx Test, RAW |
| LTS203 |
OC-3 / STM-1 PoS and RAW Record / Playback |
| LTS303 |
OC-12 / STM-4 PoS and RAW Record / Playback |
| LTS205 |
OC-3 / STM-1 PoS Protocol Analysis |
| LTS305 |
OC-12 / STM-4 PoS Protocol Analysis |
| |
Other Related Software |
| LTS200 |
OC-3 / STM-1 ATM Monitor, BERT, Tx/Rx Test, RAW |
| LTS300 |
OC-12 / STM-4 ATM Monitor, BERT, Tx/Rx Test, RAW |
| LTS202 |
OC-3 / STM-1 ATM and RAW Record / Playback |
| LTS302 |
OC-12 / STM-4 ATM and RAW Record / Playback |
| LTS204 |
OC-3 / STM-1 ATM Protocol Analysis |
| LTS304 |
OC-12 / STM-4 ATM Protocol Analysis |
| LTS206 |
OC-3 / STM-1 UMTS Protocol Analysis |
| LTS306 |
OC-12 / STM-4 UMTS Protocol Analysis |
| |
Related Hardware |
| LTS100 |
Dual OC-3 / STM-1 OC-12 / STM-4 PCI Express Card |
| LTS105 |
Portable Dual OC-3 / STM-1 OC-12 / STM-4 |
| |
DDR2 Memory Options - 512 MB, 1 GB, 2 GB |
| |
SFP Options - |
| |
Fiber cables |
| |
Fiber connector |
| |
OC-3 / STM-1 OC-12 / STM-4 Monitor Parts |
