TDM-2EV CESoPSN

PacketBand-TDM-2EV delivers high quality, completely transparent circuits across different types of packet
networks with various clocking options for different types of networks. It is shipped with an E1/T1 port plus a V.35 port, or an E1/T1 plus an X.21/V.11 port. Enabled as standard for either port or optionally both ports simultaneously.

• Highly accurate and stable clock recovery
• G.823 Synchronisation of accuracy achievable
• Precise and steady “hold-over” clock
• “Tuneable” to different network types
• Robust, reliable and professional quality
• Excellent management, statistics and diagnostics
• Various clocking options, including Multicast
• Inter-works with other PacketBand family members

PacketBand excels in delivering stable and accurately
clocked E1/T1 “leased lines” over packet networks and
benefits from Patapsco’s excellent support.

Connectivity Overview

• The PacketBand-TDM-2EV (TDM-2EV) supplies an E1 or T1 circuit over Ethernet, IP, or MPLS networks, or a V.35 or X.21 over
  Ethernet/IP port.
• Optionally both ports can be used simultaneously.
• Optionally the TDM-2EV also supports the Multicast clock recovery system which delivers highly accurate services across larger networks.
• It can be used in pairs or with other members of the PacketBand range.

Interfaces

• Single E1/T1 interface
• RJ45 120Ohm or 75Ohm (user switchable) via converter cable.
• Full G.703 E1/T1 (user selectable) or a fractional G.704
• Single V.35
• MRAC 37-way female DCE connector
• Speeds from 64k to 2.048Mbps
• Single X.21/V.11
• 15-way “D” female DCE
• Speeds from 64k to 2.048Mbps
• 10/100/1GE UTP (Unshielded Twisted Pair RJ45) interface to the WAN
• Local 10/100/1GE UTP Ethernet port
• Optional SFP cage with the appropriate SFP Module interconnects to a fibre WAN
• RJ12 management port (PacketBand is also manageable across the packet network)
• IEC connector for quality internal AC PSU (DC options available)

Clocking

• Clock recovery, accuracy and stability is key to many TDM applications. This clock recovery performance must be maintained
  when migrating to an unclocked packet network solution.
• Many types of equipment expect similar performance to that of traditional leased lines which are generally referenced to the G.823 Synchronous Interface mask. The PacketBand ranges are specifically designed and optimised to excel in this area and when used on high quality networks can meet and exceed the G.823 requirements.
• The clock recovery methods use a variety of mechanisms. These include sophisticated algorithms which allow users to “tune” the performance to match the network characteristics; after all, networks differ greatly – an extreme example being between the public Internet and a private managed networks supporting Quality of Service (QoS).

Clock Algorithms

• The TDM-2EV supports three advanced algorithms as standard.
• These are designed and optimised for different network types, broadly-speaking one for high quality managed networks with low jitter (PDV) and packet loss, one for networks with lower performance characteristics and one for applications where stability is paramount but the G.823 mask is not targeted. Within these options are two further settings allowing tighter optimisation if required.
• This means PacketBand can be configured to extract the best possible service for any given network.

Clock stability

• Clock frequency stability performance can exceed AT&T TR-62411, T1.403, G.824 and G.823 on quality networks for both Traffic and the much more demanding Synchronisation requirements.
• This is an important strength as many services will either require very accurate synchronisation to run correctly (for example mobile backhaul) or there could be multiple clock sources within the network which all require aligning accurately to ensure error-free and reliable services.
• PacketBand can deliver reliable services that clock as accurately as traditionally delivered leased lines.
• PacketBand alarms to DbManager should the recovered clock stability move outside of configured historic thresholds, giving
  immediate information should the clock deteriorate for any reason.

Clock Sources and Clocking

Although easy to use and configure, PacketBand offers customers a number of solutions for different clocking scenarios as briefly described below. Most situations will use the first two options shown, however some applications, devices and networks will benefit from the others. The PacketBand’s advantage is not only very accurate clocking and reliability, but also the flexibility to work in different modes to suit a variety of situations and applications.
A clocking hierarchy is configurable and the PacketBand automatically switches between sources and generates an Alarm.

• TDM ports
  Clock can be extracted from the attached E1/T1 user ports, although this unit is more often at a customer site with clocks
  being recovered from a remote central location, thus this remote “Slave” unit recovers clock across the packet network and clocks its attached equipment as described in “Adaptive” below.
• Adaptive
  Using sophisticated recovery algorithms, clock can be derived from any of the in-coming packet streams from a remote “Master” PacketBand. The remote “Master” would generally have a high quality clock source presented on its TDM port. This allows the“Slave” TDM-2EV to adaptively recover this clock very accurately across the packet network, in effect synchronising both devices to a common clock.
• Loop-Timing
  In instances where both ends of the circuit have a good quality
  common clock source (for example ISDN clocks into PABXs) both
  TDM-2EVs can be set to clock from this local E1/T1 source.
• Multicast
  The PacketBand-TDM-2EV optionally supports an innovative out-of band clocking method via Multicast services which has three key advantages.
  Multicast is an efficient method of transporting unidirectional (simplex) traffic from one main transmission location to multiple remote sites. PacketBand utilises this feature to transmit a low data-rate clock stream to a Multicast-enabled router and for remote PacketBands to “join” Multicast groups and recover the clock. This optional facility, together with the PacketBand’s excellent clock recovery accuracy, makes the system ideal for larger networks and in particular for X.21 and V.35 services (see below).
  The Multicast capability means PacketBand separates the clock recovery data from the bulk user data. Larger networks with
  multiple “hops” can deliver not only improved clock synchronisation, but there are network design/loading/QoS and
  resiliency benefits as well because the bulk of the network traffic (user data) is no longer used for clock recovery and can therefore be transmitted at a lower QoS level.
  X.21 and V.35 leased lines are normally provided with the clock coming from the carrier network. The Multicast feature means all customer sites can be easily synchronised, particularly where no clock source is available at the end user site.
  When delivering clocked services to customer sites the Multicast feature ensures all customer sites are clock-locked/synchronised.
  This is covered more extensively in the clocking White Paper.
• Internal
  If no external quality clock is available, the TDM-2EV can use its internal oscillator. Various oscillator options are available (see below).
• Clock hold-over
  Problems in the packet network, for example a sudden increase in jitter or an interruption in packet delivery, can cause an
  unwanted movement in the recovered clock. To avoid this PacketBand enters a “hold-over” state, maintaining the recovered
  clock at the last value prior to the problem. This means the clock is always stable irrespective of issues within the network. The mid range oscillator option and timing circuits within the TDM-2EV maintain this hold-over clock to within 15ppb.
  A document covering the various clocking options is available on the web site. For more information and assistance please contact Patapsco.

Oscillators

• The quality of the oscillator when recovering the clock across the packet network is very important. The receive PacketBand running “Adaptive” clocking uses a variety of different information and many calculations to ascertain how to modify its on-board oscillator’s output to match the clock of the remote or “master” end.
• It can be seen that the more stable the on-board oscillator, the more stable the recovered clock.
• TDM-2EV is fitted as standard with a 1ppm TCXO oscillator with a low cost upgrade option to a high quality Temperature Stablised Enhanced Stratum3 TCXO oscillator which is ideal for all but the very most exacting applications. This delivers +/-12ppb over the full temperature range and typically in “Hold-Over” better than +/- 15ppb in a 24 hour period with the unit operating at ambient room temperature.
• For even further improved stability, particularly in environments where the temperature can change rapidly, the TDM-2EV is available to order with a slightly larger chassis and a temperature-controlled fan.
  An oven-controlled OCXO oscillator is also available.
• Please contact Patapsco or your supplier to discuss this area in more detail.
• Very few applications require the OCXO version as the mid range enhanced TCXO has such a high performance. Note that the quoted figures are for the stability of the on-board oscillator itself, not the actual clock provided to attached devices.
• PacketBand adds/subtracts from this internal clock to derive the recovered clock which in the majority of instances is significantly superior to the base oscillator with zero wander/drift over a period of time.
• Oscillators comply with G8261/Y.1361 and detailed specifications are available on request.

PDV (Packet Delay Variation or jitter)

• The PacketBand-TDM-2EV supports up to 400mseconds of PDV or jitter depending upon configuration parameters. This is normally far in excess of the PDV experienced on private networks and many Internet connections.
• The jitter buffer can be set in msec granularity and adjusted manually or automatically whilst the circuit is in place, overcoming ‘skew’ at start up time caused by the first packet in the buffer arriving later or earlier than average.
• The buffer re-orders out of sequence packets. If packets are lost by the network the data to be transmitted to the attached device by PacketBand is user configurable. Statistics are available to provide information on usage (see below).

Ethernet and Packet Handling

• Support for 10/100/1GE.
• Support for packets up to 1632 bytes in size (10,240 bytes August 09).
• Single MAC and IP address, Default Gateway and SubNet Mask,
• support for DHCP. Disordered packets are reordered automatically.

Prioritisation

• TDM packets can be assigned IP Diffserv (DSCP) or ToS and 802.1p CoS values.
  PacketBand supports full 802.1q tagging and the associated 802.1p CoS prioritisation levels.
  All egress packets including TDM links can be prioritised across four output queues using CoS (802.1p) or Diffserv/ToS values.

VLAN Handling

• PacketBand’s powerful and latest-generation on-board packet switch offers advanced 802.1Q VLAN facilities such as multiple TAGing, TAG insertion/removal, port routing based on default TAG or a Global TAG table. Egress packets can be TAGed, have multiple TAGs or be stripped of TAGs according to configuration.
• PacketBand also supports Provider Mode whereby customer packets are TAGed for transport across the network with the TAGs being removed before passing back to the customer at the far end.

Link Aggregation Control Protocol (LACP)

• This powerful optional feature enables two or more Ethernet ports connected between PacketBand and the network switch to be aggregated together as defined in LACP IEEE 802.3-2005.
• This aggregation makes it appear as if the multiple links are acting as a single high capacity circuit. Furthermore, it adds a level of redundancy with automatic rerouting. See separate document on LACP.

Rapid Spanning Tree Protocol (RSTP)

• RSTP (as defined in IEEE 802.2EV-2004) identifies the means to build an Ethernet network which contains physical loops between bridges. This facility enables PacketBands to be connected to more than one network switch via different circuits and to provide an automatic fall-back in the case of a link failure.

Rate Limiting

• Individual packet ports can have the traffic capacity restricted in various ways, even though the access is 10/100/1GE. This is
  particularly useful on the second Ethernet port when connected to user LANs where the main link to the network could be “swamped” by data from attached devices.

Overheads

In order to transport TDM data over the packet network, there is some overhead caused by encapsulating the data inside the packet
network protocol.

• The Protocol
  PacketBand supports a number of different packet network protocols. The user’s choice of a particular network will affect the overall size of packet headers.
• Size of Packet
  PacketBand supports a configurable packet size per Logical Link. There is a trade off between transmitting small packets at a fast rate (low latency, larger overhead due to protocol headers) and transmitting larger packets at a slower rate (bigger latency, smaller overhead).
  Typical overheads are in the 5% to 10% range. Patapsco have a spreadsheet available which identifies overheads based on a
  number of different parameters. Contact Patapsco or your supplier.

Latency

• Processing Delay
  The latency or processing delay through each PacketBand is
  optimised to be as low as possible. Typical processing delay is less
  than 1msec.
• Transmit Delay
  This is the time necessary to wait for sufficient incoming data to arrive from the attached device so a packet of the configured size can be built and transmitted over the network. This is typically around the 1msec range. See also 6.2 above.
• Jitter
  Packet network networks differ in how consistently packets pass though them; some packets take more or less time than the average. PacketBand provides a synchronous clocked circuit to the attached devices and therefore has to have data ready and available for the relevant clock pulse. PacketBand buffers the fast packets so as to ensure the slow ones can arrive in time to be used. The amount of buffering is user-configurable and will depend upon the performance of the network.
  Note this buffering is only required on the PacketBand receive data path and the amount of buffering needed (which equates to latency) is a result of the network, not PacketBand.
• Transit Delay
  All IP networks have different average transit delays. These vary depending upon a large number of criteria, including the number of “hops” and whether satellites are involved. Typically, domestic links are very fast, inter-continental around
  60msec and a satellite can add 250msecs. Please consult your network supplier.
• Summary:
  between any pair of PacketBands on a terrestrial network, the most significant element contributing to latency is size of
  the Jitter Buffer (which is user configurable). This is directly dependant on the performance of the network and outside the control of PacketBand.

CESoP Modes

• PacketBand supports both “Structure Aware” and “Structure Agnostic”
  modes. Complies with ITU-T recommendation Y.1413, IETF PWE3 draft
  standards CESoPSN, SAToP and CES draft IAs from MEF and MFA.

“Grooming”

• If the TDM-2EV is running a channelised G.704 trunk then it may be communicating with many remote locations, grooming the multiple circuits into a single G.704. TDM-2EV can optionally support 16 or 31 links.
  The IP ToS or Diff Serv and Ethernet VLAN Tagging is configurable on a per-link basis.

Approvals

• All approvals completed in a UK Accredited laboratory. CE marked.
  Safety and Emissions (EMC) approvals (CE and FCC)
  PacketBand TDM-2EV is RoHS compliant without the use of any “exceptions”.

Management

• Overview
  
  PacketBand can be locally or remotely configured using Patapsco’s easy-to-use high functionality DbManager GUI software.
  DbLite is supplied free with each unit.
• Optionally available are different versions to support requirements for larger or more integrated networks. It is sophisticated but simple to use via an intuitive Graphical User Interface (GUI) which controls, configures and monitors individual Patapsco units and complete networks, currently Microsoft-based, it can also generate SNMP Traps and Alarms.
• The DbManager supplied with PacketBand (DbLite) allows control and visibility of a single PacketBand at any one time via a single PC.
• Other options support multiple real-time work-stations, a network of PacketBands and links, and have additional capabilities such as SNMP Traps & Alarms and continuous polling of devices.
• A document identifying the differences between DbLite and other versions is available.
• Used by various organisations with different network sizes - up to and including carriers - versions of DbManager deliver a networkwide view of all PacketBands and links via a 4-layer “tree-structured” overview. The status of all PacketBands and links are easy to identify with Alarms being colour coded and passed up the tree.
• Separate windows provide Event and Alarm information with the ability for operators to add comments etc. Different access levels and passwords provide operators with appropriate capabilities within the program.
• An option to encrypt the management traffic across the packet network is available, together with a key management and update system.
  
  
• Configuration Changes
  
  Configuration changes on PacketBand are made via the DbManager. All configurations can be stored on DbManager.
• Installations require little or no expertise in the field as most configurations (other than IP address) can be performed remotely.
• Configurations are held in non-volatile memory.
• DHCP is supported.
  
  
• Management Tools
  
  A wide number of statistics are available for the E1/T1 and
  V.35/X.21 circuits and Ethernet ports.
  
       Alarms/Events
  
  
  • All Alarms are reported back to the DbManager and
    presented in a dedicated window with descriptor.
    Events and Alarms are held within non-volatile memory locally
    in the TDM-2EV for access via DbManager.
    A dry contact alarm relay is available in the RJ12 port.
    
    
       Graphs
  
  
  • DbManager and PacketBand provide several network monitoring tools available with graphical out-put:
    • Maximum, Minimum and Average jitter buffer usage over time. This useful screen shows how the network and link
    are performing. Particularly useful information includes Lost and Late packets and jitter buffer usage figures.
    • Average network jitter over time A graphical representation showing Minimum, Maximum and Average buffer usage which provides important information on network performance.
    • Recovered clock movement over time
    This graph shows frequency stability and the status of the
    acquiring clock. These are invaluable tools for optimising PacketBand and for acquiring information on network performance.
    These statistics, which are updated for each Link every 10 seconds, gives accurate and invaluable information on the
    performance of the network and are vital when installing. The information also identifies whether the jitter buffer settings are correct and if the jitter buffer can be reduced to remove any unnecessary latency.
    
    
     “Sniffer” port


• The second Packet port on PacketBand can be configured as
  a “sniffer” port duplicating TX and/or RX packets on the
  network Packet Port. This is a very useful diagnostic tool.
  
  
     Loop-Backs


• Loops can be placed on the TDM ports in either direction and
  at the Ethernet level.
  
  
    Pings


• PacketBand generates Ping/Trace Route and responds to Ping
  and UDP Echo requests.
  
  
    Boot Test


• Internal test on power-up with results visible via DbManager.
  
  
• Software/Firmware Updates
  
  New software can be loaded via the DbManager to PacketBand- TDM. New software is loaded to the off-line sector of Flash and is confirmed via a CRC. Users can switch to the new software at any time. DbManager can load new code to multiple PacketBands simultaneously.
  

Power

• Internal High-Quality AC supply
  
  Auto-sensing, standard IEC input.
  
  
• Optional DC Supplies 48VDC or 24VDC (nominal)
  
  Replaces AC supply. Specify when ordering.
  

Specifications

• A. Clock Recovery
  Advanced algorithms tuneable for different
  network characteristics as standard.
  Capable of exceeding G.823 Synchronous
  Interface requirements (subject to network
  performance)
• B. TDM port (E1)
  RJ45 connector
  Presents as DCE (crossed cable for DTE)
  120 Ohm
  75 Ohm user-selectable via converter cable
  G.703 unstructured
  G.704 channelised
  ITU G.706
  Selectable CRC4/non-CRC4
  HDB3
  Transparent to user signaling
• C. TDM port (T1)
  RJ45 connector
  Presents as DCE (crossed cable for DTE)
  100 Ohm
  Unframed 1.544Mbps
  Framed 1.536Mbps (robbed-bit)
  ESF or D4 selectable
  B8ZS or AMI selectable
  Transparent to user signaling
• D. V.35 port
  Standard MRAC
  37-way female DCE connector
  Speeds from 64kbps to 2.048Mbps
• E. X.21/V.11 port
  Standard 15-way “D”
  Female DCE connector
  Speeds from 64kbps to 2.048Mbps
• F. Ethernet Interfaces
  2 x RJ45 UTP
  10/100/1GE
  Auto-sensing or manual
  Optional SFP cage (module not supplied) for
  various fibre modes
  1 network and 1 or 2 user ports (second
  port using SFP)
• G. Local Management Port
  RJ12
  Asynchronous
  Auto-sensing to 115kbps
  Also remote access via packet network
• H. Oscillator Performance*
  Standard
  Hold-over 24hrs 0.5ppm
  Aging per day 20ppb
  Temperature Stability 0.600ppm
  Enhanced
  Hold-over 24hrs 15ppb
  Aging per day 10ppb
  Temperature Stability 12ppb
  Enhanced (from August ‘09)
  Hold-over 24hrs 4ppb
  Aging per day 0.5ppb
  Temperature Stability 14ppb
  Oven
  Hold-over 24hrs 10ppb
  Aging per day 0.3ppb
  Temperature Stability 10ppb
• I. IP & MAC Address
  Single MAC address, IP address, subnet
  mask and default gateway
  Support for DHCP
• J. Configuration
  Held in non-volatile memory
• K. Power (AC)
  Internal via IEC connector
  Auto-sensing 96VAC-240VAC
  Max consumption 0.2Amps RMS @230VAC
  MTBF 400,000hrs
• L. Power (DC)
  
  1. Nominal -48VDC
  4mm terminal block
  -33VDC to -75VDC
  0.35A max
  MTBF 1,790,000hrs
  
  2. Nominal -24VDC
  4mm terminal block
  -18VDC to -75VDC
  0.55A max
  MTBF 800,000hrs
  
  
• M. Dimensions & Environment
  Metal chassis and front/rear panels
  W – 225; D – 200; H – 44mm
  Weight – 0.9Kg/2lb
  Optional 19” rack-mount kit; 1 unit per 1U
  or 2 units side-by-side per 1U
  Operating Temperature -20°C to +50°C
  with convection cooling
  Humidity 10-90% non-condensing
  Optional larger chassis with temperature controlled
  fan -20°C to +60°C
• N. Maintenance
  There are no serviceable parts or
  maintenance required
• O. Approvals
  EMC
  EN55022:1988
  EN55014:1988
  EN61000-3-2/3:1995
  AS/NZ CISPR22:2000
  FCC Part 15(B)
  RoSH Compliant without the use of
  exceptions
• P. Safety
  EC EN60950-1:2002
  ACA TS001:1997
  ACS/NZ60950:2000
  AS/NZS3260:1993
  IEC950