Newsletter: GL Enhances ML PPP & PPP
Emulation & Analysis
Welcome to a July 2010 issue of GL Communications' Newsletter providing information on enhancements introduced
to our ML PPP Analyzer and MC ML PPP Emulator –
protocol tools that emulate and analyze Point-to-Point (PPP), Multi Link Point to Point (ML PPP), and Multi Class ML PPP
ML PPP bundles multiple link-layer channels into a single network-layer channel. Data sent through this channel is
distributed among all the links. It is a technique used to derive larger bandwidth pipe by aggregating smaller bandwidth
pipes e.g. from multiple T1s or E1s.
GL's flexible and versatile MC ML PPP Emulator is both GUI and script based. The
software is capable of generating and receiving MC ML PPP and PPP traffic (with or without impairments). Traffic source can
be sequence number, HDL files (containing packets/frames), flat binary file, user-defined frames (ASCII HEX file), and
The Multi Class extension to ML PPP allows a sender to fragment the packets of various priorities into multiple classes
of fragments, and allows high-priority packets to be sent prior to lower priority fragments.
MC ML PPP emulator can now be configured as a router or as a Bridge to establish
connections and route traffic between LANs.
The software runs on GL's T1 E1 Analyzer platforms which are available as powerful HD PCI cards as well as portable
USB based units.
ML PPP Analyzer enhanced with Packet Data Analysis (PDA)
GL's ML PPP Packet Data Analyzer (PDA) is a real-time IP and VoIP analyzer that non-intrusively analyzes and captures
live IP traffic, and segregates them into SIP / H323 / Megaco / MGCP calls. It also collects statistics, CDRs, detailed protocol
traces, ladder diagrams, and a host of other useful information about VoIP calls. Its real-time nature makes it an outstanding
tool for live monitoring of VoIP traffic as well as long-term traffic statistics gathering. It can also monitor, report, analyze,
and capture calls for infinite time, limited only by the finite space of your hard disk or network hard drive!
Important features of Packet Data Analyzer (PDA)
- Supported protocols - SIP (Session Initiation Protocol RFC 2543 and RFC 3261), Megaco RFC 3525, Megaco RFC 3015,
MGCP, H323/H225, and RTP
- Full RTP Analysis with audio capture/playback supported for all common codecs
- Provides the registration summary of each SIP registration including the user agent, registrar, status, registered time,
expiry time, time to live, and remaining time
- Supports saving the selected calls from traffic analyzer into *.HDL or *.PCAP formats
- T.38 Analysis - The application has the call graph and T.38 ladder diagram display. User can decode T.38 frames
received over VoIP calls and can have ladder diagram for T.38 traffic flow, reassemble the fragmented data and to identify
the T.30 message from it
- Triggered Actions and E-mail Support
- Record audio and video data of a session to a file in QuickTime format
- R factors/MOS supported for more audio and video codecs: Mulaw, Alaw, G726 (40 kbps), G726 (32 kbps), G726
(24 kbps), G726 (16 kbps), GSM610, G729, G729B, AMR, ILBC (20 msec), ILBC (30 msec) and SPEEX, EVRC, EVRCB
- Call Quality Of Service (QOS) for all calls with E-Model based (G.107) Mean Opinion Score (MOS) and R-factor with
individual and summary statistics presented in graphical and tabular formats
- Alert Summary tab provides summary of the each alerts that have occurred during the analysis. Each summary has the
following columns: Call#, Protocol, Message, Type, Threshold, Value, Caller, Callee, CallId
- Support for H.263+ provides video capture and videoconference monitoring capability
For comprehensive information on the product, please refer to ML PPP Analyzer
Enhancements to the MC ML PPP Emulator application
- PPP Multiplexing:
The MC ML PPP Emulator application has been added with Multiplexing feature that sends multiple PPP encapsulated
packets in a single PPP Multiplexed frame, and each PPP encapsulated frame within a multiplexed frame is called a PPP
sub-frame. And sub-frames are concatenated to a make a single PPP multiplexed frame by inserting a delimiter before the
beginning of each sub-frame, and as a result, the PPP encapsulation overhead per packet is reduced.
During NCP negotiation phase, PPP multiplexing can be enabled by using the PPP Mux Control Protocol (PPPMuxCP),
and once the PPPMuxCP has been negotiated, the transmitter may send multiplexed ppp frames.
- RTP Compression (CRTP):
ML PPP Emulator now supports RTP compression. During NCP negotiation phase of PPP, RTP compression sub-option
is used to enable the RTP compression. Once RTP compression sub-option is negotiated, IP/UDP/RTP compression will
enabled conforming to RFC 2508
Other Important existing features include:
- ML PPP Emulator as a Router
The Emulator allows users to setup routing table by configuring IP-Address and Mask. Once configured, the Emulator
forwards the IP packets which match routing criteria over T1 E1 links. Emulator respond to all ARP requests whose IP
addresses present in routing table.
The emulator allows mapping of user defined class of service into ML PPP class/ PPP Link based on length, source IP
address, destination IP address and Type Of Service of the received IP packets, set in priority dialog table.
- ML PPP Emulator as a Bridge
When the emulator is configured to act as bridge between two networks, all ARP and traffic (checked against the priority
table) received from the network is encapsulated as BPDU (Bridging Protocol Data Unit) and streamed over T1 E1 links. The
Emulator on another network removes BPDU header, either converts to Ethernet traffic or adds Ethernet header and streams
to the destination.
- IP compression
MC ML PPP Emulator supports the following IP compression standards: Van Jacobson Compression and IP Header
MC ML PPP Emulator supports various impairments at PPP layer - CRC error, frame error, frame duplication, and more.
Also supports various Fragment/Packet impairments for each Class at ML PPP level.
For comprehensive information on the product, please refer to MC ML PPP Emulator
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