Eclipse IDU GE 20x White Paper ETSI

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IDU GE 20x ETSI The IDU GE 20x is an advanced Gigabit Ethernet + TDM wireless for frequency bands 5 to 38 GHz. It provides exceptional flexibility and performance when establishing new Ethernet networks, or for migrating existing TDM networks to Ethernet.

This paper introduces the features and basic operation of the IDU GE 20x, and illustrates typical applications.

Contents Introduction to IDU GE 20x

Capacity and Bandwidth Options

IDU GE 20x Compatibility

DAC GE Module

Ethernet Modes of Operation

Transport Channels

Basic Ethernet Port Settings

Priority Mapping

Flow Control

Disable Address Learning

Maximum Frame Size

Link Status Propagation

VLAN Tagging

Ethernet Diagnostics

Wayside Traffic Module

Alarm I/O Module

IDU GE 20x Layout

Link Aggregation

RWPR

Link Protection

Network Applications

Broadband Backhaul

Edge Terminals in an INU Backhaul Network

GigE Inter-Site Company Network Connection: Example No. 1

GigE Inter-Site Company Network Connection: Example No. 2

Metro Edge Switch

Summary

Glossary

3/26/2008 IDU GE 20x ETSI WhitePaper_2.doc Page 1 of 22 www.harrisstratex.com

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Introduction to IDU GE 20x IDU GE 20x is a high capacity microwave radio for transport of native Gigabit Ethernet to 360 Mbit/s plus up to 20xE1 waysides. Depending on the required throughput, channel bandwidths range from 3.5 to 56 MHz, with modulation options from QPSK to 256 QAM. It is interfaced to its ODU using a single coaxial cable.

The IDU includes an intelligent Layer 2 switch with two customer 10/100/1000base-T electrical ports, and an optional SFP port for 1000Base-X optical or 1000Base-T electrical. These interface to one or two transport (link) channels using transparent, VLAN or mixed operational modes.

The switch function includes link aggregation, fast-switched RSTP, comprehensive QoS options, VLAN tagging, and jumbo frame options.

Link capacity may be fully assigned to Ethernet, between Ethernet and up to 20xE1 circuits, or to E1 circuits only. Capacity is licensed.

IDU GE 20x can be air-interfaced to an Eclipse Node comprising the INU, DAC GE or DAC ES, and ODU 300. Where E1 channels are required, a DAC 4x or DAC 16x is included. Similarly an AUX is included where external Alarm I/O interfaces are required.

Where protected 1+1 hot-standby or space diversity operation is required, it is configured by adding a second IDU GE 20x.

Mechanically, it complies with ETSI 1RU half-rack specifications (240 mm rack depth). Figure 1. IDU GE 20x with ODU

3/26/2008 IDU GE 20x ETSI WhitePaper_2.doc Page 2 of 22 Copyright 2008 Harris Stratex Networks, all rights reserved.

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Capacity and Bandwidth Options IDU GE 20x Ethernet capacity and bandwidth options are indicated in Figure 2 and detailed in Table 1. PDH-only capacity and bandwidth options are indicated in Figure 3

00, or 360 Mbit/s.

or Ethernet traffic, or assigned between Ethernet and up to 20xE1 waysides.

For configurations where available link capacity is fully assigned to Ethernet, the capacity for Ethernet is reduced by 2 Mbit/s for each E1 assigned. Figure 2. Ethernet Throughput and Channel Bandwidth Options

and detailed in Table 1.

Three cost and performance optimized ODUs support the options:

ODU 300sp. Standard performance for capacities to 80 Mbit/s on bands 7 to 38 GHz. Modulation is QPSK or 16 QAM.

ODU 300hp. High performance for capacities to 360 Mbit/s on bands 6 to 38 GHz. Modulation options extend from QPSK to 256 QAM.

ODU 300ep. Extended performance for capacities to 360 Mbit/s. It is required for 5 GHz and is an option for 13 and 15 GHz. Modulation options extend from QPSK to 256 QAM.

The base license (no license required) supports a maximum capacity of 20xE1 PDH. License options enable Ethernet in steps of 50, 100, 150, 2

The maximum capacity for each licensed option may be used f


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Figure 3. PDH Capacity and Channel Bandwidth Options

Table 1. IDU GE 20x Capacity/Bandwidth Options

Ethernet BW, Mbit/s

Max. NxE1 Capacity (1)

Channel BW, MHz

Modulation License Ethernet (2)

10 5xE1 3.5 16 QAM Level 1

10 5xE1 7 QPSK Level 1

20 10xE1 7 16 QAM Level 1


30 16xE1 7 64 QAM Level 1

40 20xE1 14 16 QAM Level 1


50 20xE1 14 32 QAM Level 1

65 20xE1 14 64 QAM Level 1

80 20xE1 28 16 QAM Level 2

100 20xE1 28 32 QAM Level 2

130 20 x E1 28 64 QAM Level 3

150 20xE1 28 128 QAM Level 3

150 20xE1 56 16 QAM Level 3

200 20xE1 28 256 QAM Level 4

200 20xE1 40 128 QAM Level 4

200 20xE1 56 64 QAM Level 4

250 20xE1 56 64 QAM Level 5

310 20xE1 56 128 QAM Level 5

360 20xE1 56 256 QAM Level 5

1. For each configured E1 the Ethernet BW reduces by 2 Mbit/s. Maximum capacity for NxE1 operation is 20xE1. 2. NxE1 operation is included in the base license and in all Ethernet licenses. If IDU GE 20x is configured for NxE1

operation only, no license is required. 3. Not all options may be available at this time. Check with Harris Stratex or your supplier.


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IDU GE 20x Compatibility IDU GE 20x can be over-air interfaced to:

An INU/INUe fitted with a RAC 30v3, RAC 30v2+, or RAC 3X. Ethernet traffic is terminated on a DAC GE or DAC ES. E1 traffic is terminated on a DAC 16x or DAC 4x. External alarm I/O interfaces are terminated on an AUX.

IDU ES for Ethernet and up to 8xE1.

IDU 300 20xV2 for up to 20xE1 only.

Table 2 indicates current and projected compatibility. Table 2. IDU GE 20x Compatibility with INUs and Other IDUs

Ethernet BW Mbit/s

BW MHz

Modulation RAC 30v3 & RAC 30v2+

RAC3X IDU ES IDU 20xV22

10 7 QPSK X N/A X X

10 3.5 16 QAM X1 N/A X N/A

20 7 16 QAM X N/A X X

20 14 QPSK X N/A N/A X

30 7 64 QAM X N/A X X

40 14 16 QAM X N/A X X

40 28 QPSK X N/A X X

50 14 32 QAM X1 N/A X N/A

65 14 64 QAM X N/A X N/A

80 28 16 QAM X N/A X N/A

105 28 32 QAM X N/A N/A N/A

130 28 64 QAM X X N/A N/A

150 28 128 QAM X N/A X N/A

150 56 16 QAM N/A X N/A N/A

190 28 256 QAM N/A X X N/A

200 40 128 QAM N/A X N/A N/A

200 56 64 QAM N/A X X N/A

1. RAC 30v3 only. 2. For equivalent NxE1 rates only.

DAC GE Module The Layer 2 switch in the IDU GE 20x operates as a DAC GE module. Relevant specifications are identical to the DAC GE plug-in for the INUs. Features include:

Two 10/100/1000Base-T ports plus an optional port for an SFP 1000Base-LX (optical) or 1000Base-T (electrical) transceiver

User ports mappable to one or two transport channels for transmission over the radio link

Programmable switching fabric: transparent, VLAN, or mixed mode

Capacity increments of Nx2 Mbit/s to 360 Mbit/s

Extremely low latency, less than 360 microseconds for 2000 byte packets

Comprehensive Ethernet QoS policing and prioritization options

VLAN tagging (802.1Q and Q-in-Q)

Flow control through 802.3x pause-frame option


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Jumbo frames to 9600 bytes

Comprehensive RMON and performance indicators

Figure 4 illustrates the basic operational blocks. Two RJ-45 electrical ports and one optional SFP optical or electrical port connect to an Ethernet switch, which provides the bridge/switch and queuing functions between the ports and two transport channels, C1 and C2. The gate array (FPGA) provides signal framing and the interface to the IDU GE 20x radio module, where Ethernet traffic can be configured to ride side by side with up to 20xE1 waysides.

The DAC GE MAC address register supports 8192 entries.

The switch analyzes the incoming Ethernet frames for source and destination MAC addresses and any priority tagging (802.1Q or Diffserv), and determines the channel/port over which the frames will be delivered and their prioritization through the switch.

Ethernet throughput is determined by the configured port and channel speeds, and the capacity configured on the radio link. Figure 4. IDU GE 20x Ethernet Module Block Diagram

Table 2. SFP Optical Port Specifications

Wavelength: 1310 nm Single Mode

Maximum launch power: -3 dBm

Minimum launch power: -9.5 dBm

Link distance Distances to 10 km / 6 miles with 9/125 m optical fiber; 550m / 600 yards with 50/125 m or 62.5/125 m fiber

Table3. SFP Electrical Port Specifications

RJ-45 connector with integrated magnetics

Compatible with IEEE 802.3:2000

Link lengths at 1.25 Gbd: up to 100 m per IEEE 802.3

Compatible with both shielded and unshielded twisted pair Cat 5 cable

Ethernet Modes of Operation IDU GE 20x supports three operational modes, transparent, mixed or VLAN, which determine the port-to-port and port-to-channel relationships (switching fabric) within the L2 switch.

These modes, illustrated below, apply to non-protected IDU GE 20x operation, and are compatible with INU DAC GE modes.

Modes for protected IDU GE 20x operation differ. Refer to Link Protection, page 13.

Transparent Mode This is the default, broadcast mode. All ports and channels are interconnected. It supports three customer LAN connections (ports 1, 2 and 4), with bridging to two


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separate transport channels (C1 or C2). To avoid a traffic loop only C1 or C2 is used over the common radio path. Figure 5. Transparent Mode Port and Channel Assignment

Mixed Mode Mixed Mode provides a two-LAN connection solution, where P1-C1 provides dedicated transport for port 1 traffic. A second transparent/broadcast mode LAN connection is provided with P2, P4 and C2 interconnected. Figure 6. Mixed Mode Port and Channel Assignment

VLAN Mode VLAN Mode supports three separate LAN/VLAN connections. LAN 1 is the same as for Mixed Mode, where dedicated transport is provided for port 1 traffic. For ports 2 and 4, two separate (virtual) LANs are multiplexed to C2, with internal Q-in-Q tagging of the frames ensuring correct end-to-end matching of LANs or VLANs over the link. Figure 7. VLAN Mode Port and Channel Assignment

Transport Channels One or both channels combined can be configured to support Ethernet bandwidths from 10 to 360 Mbit/s. Maximums are determined by the configured link capacity.

With both channels configured (Mixed or VLAN mode), both are operated over the same radio path to provide separate transport connections.

Basic Ethernet Port Settings The following settings are prompted in the DAC GE configuration screen of the IDU GE 20x.

Enabled / Disabled. A port must be enabled to allow traffic flow. Port Name. A port name or other relevant port data can be entered.

Speed - Duplex. Provides selection per-port of auto or manual settings for speed and half or full duplex operation. In auto, the IDU GE 20x self-sets these options based on the traffic type detected.


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Mdi/MdiX. Provides selection per port of auto or manual settings for the interface type; Mdi or MdiX (straight or cross-over respectively).

Priority. Provides a four-level, low, medium-low, medium-high or high priority setting for each port. This prioritization only has relevance to ports using a shared channel. Priorities are fair-weighted to ensure that low priority traffic gets some bandwidth when availability is restricted.

Port Up. Indicates that an Ethernet connection with valid Ethernet framing has been detected.

Resolved. Indicates that the port connection has been resolved for an auto selection of speed-duplex.

Priority Mapping Priority Mapping provides selection of queue-controller operation for the following options. A selection applies to all ports.

Port Default. Enables the setting of a four-level port priority on each of the three ingress ports. See Priority in Basic Ethernet Port Settings above.

802.1p. Provides prioritization based on the three-bit priority field of the 802.1p VLAN tag. Each of the possible eight tag priority values are mapped into a four-level priority level. Mapping is user configurable.

DiffServ. Provides prioritization based on the six bits of the IP DiffServ header. Each of the possible 64 levels are mapped into a four-level priority level. Mapping is user configurable.

No priority. Incoming packets are passed transparently.

Flow Control Flow Control is implemented through use of IEEE 802.3x pause frames. These tell the terminal node to stop or restart transmission, to ensure that the amount of data in the receive buffer does not exceed a high water mark.

The receiver signals to the transmitter to stop transmitting until sufficient data has been read from the buffer, triggered by a low water mark, at which point the receiver signals to the transmitter to resume transmission.

To be effective, flow control must be established from the originating source through to the end point, and vice versa, which means the equipment connected to the IDU GE 20x ports and beyond should also be enabled for flow control.

Disable Address Learning Address Learning is default implemented to support efficient management of Ethernet traffic in multi-host situations. The option to disable Address Learning is typically used in a ring network where protection for the Ethernet traffic is provided by an external RSTP switch. To avoid conflict between the self-learning functions within the IDU GE 20x and external RSTP switches during path failure situations, the IDU GE 20x capability must be switched off. Failure to do so means that in the event of an Ethernet path failure, and subsequent re-direction of Ethernet traffic by the external switch to the alternate path, the IDU GE 20x will prevent re-direction of current/recent traffic until its address register matures and deletes unused/un-responsive destination addresses. This can take several minutes.

Maximum Frame Size Maximum Frame Size sets the largest size frame for the interface, which determines the largest datagram than can be transmitted without it being broken down into smaller units


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(fragmented). IDU GE 20x supports one-way jumbo-frames up to 9600 bytes, or to 7500 bytes both-ways. The configurable range is 64 to 9600 bytes.

Link Status Propagation Link Status Propagation enables externally connected equipment to detect the status of an IDU GE 20x link with minimum delay. It operates by instantly forcing a port shutdown at both ends of the link in the event of a channel failure, such as a path fade, or at the far end of a link in the event of an Ethernet cable disconnection, or external device failure on a DAC GE 20x port.

A shutdown is immediately detected by the connected equipment to initiate relevant alarm / recovery action, such as reconvergence in an RSTP network. Similarly, port-up is immediately re-instated when the link failure is cleared.

VLAN Tagging IDU GE 20x supports VLAN tagging on a per-port basis:

802.1Q: Ingressing untagged frames are tagged. Tagged frames are ignored.

802.1Q-in-Q: Ingressing untagged and tagged frames are tagged. Those with an existing tag are double tagged.

Tags can be stripped or retained at the far end of the IDU GE 20x link. Tagging options include 802.1p CoS (Class of Service) prioritization, the setting of a VLAN membership ID, and a VLAN membership filter.

These tagging options are available on ports P1, P2 and P4 using Transparent mode, and on ports P2 to P4 for Mixed mode.

With this VLAN tagging capability, IDU GE 20x can tag, 802.1p prioritize, and aggregate LAN or VLAN traffic from two or three ports onto a common trunk/channel. At the far end of the IDU GE 20x link, the options are to remove the VLAN tags applied by IDU GE 20x, or allow them to be retained intact for VLAN traffic management at downstream devices.

For VLAN tagging options on protected IDU GE 20x links, refer to Link Protection, page 13.

Ethernet Diagnostics Diagnostics screens capture Ethernet performance and history. The data includes:

Port/channel status.

Configured capacities.

Graphed current Rx and Tx throughputs and discards per port and channel.

Graphed historical Rx and Tx throughputs, frame type and discards per port and channel.

Comprehensive RMON performance statistics per port and channel.

Event history.

Wayside Traffic Module The Wayside Traffic Module supports 20xE1 tributary circuits. Each is accessed on an RJ-45 connector. Options are provided for 75 ohms unbalanced or 120 ohms balanced connections.

Diagnostics support the application of trib and radio facing loopbacks, AIS insertion, and a PRBS generator and receiver for trib BER measurement.

Line isolation and surge protection are included.


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Alarm I/O Module This module supports two TTL alarm inputs and four Form-C relay outputs.

Individual alarm inputs can be mapped to any output within an Eclipse network. Similarly, individual internal events can be mapped to any output.

Multiple input or internal events may be mapped to a common output. Mapping is achieved using IP addressing for the destination IDU, or if the destination is an Eclipse INU/INUe, to its IP address plus the slot location and output number for the AUX plug-in.

IDU GE 20x Layout Figure 8 illustrates the IDU GE 20x front panel layout and interfaces. Figure 8. IDU GE 20x Front Panel Layout

No Item/Label Description

1 Rack Ear and Grounding Stud

Rack attachment bracket for the IDU. One ear has a grounding stud for IDU grounding. The ears provide flush-with-rack-front mounting.

2 -48 Vdc 2-pin D-series 2W2C power connector. Includes screw fasteners.

3 Fuse 5A time-lag fuse and power on/off switch. ON is when the fuse head is in the vertical position; OFF is when the head is rotated to the horizontal 0 position.

4 To ODU Type N female connector for ODU cable connection. Normally a jumper cable is fitted to connect to a lightning surge suppressor located at the cable entry point to the building.

5 Trib 1-20 RJ-45 connector assemblies for wayside tributary connections; one RJ-45 port per E1. Termination is set for 75 ohm unbalanced or 120 ohm balanced in Portal. Cable options provide extension to BNC connectors for unbalanced, or to RJ-45 plugs or unterminated wires for balanced operation.

6 Ethernet RJ-45 traffic ports. Ports 1 & 2.

Connector assembly for 10/100/1000Base-T Ethernet traffic. The green connection-status LED is on for a valid Ethernet connection. Off indicates no connection or an invalid connection. The orange activity LED flashes to indicate Ethernet traffic on the port. The LED does not flash (is solid on) when there is no traffic activity. (Activity LED is off when the connection status LED is off).

7 Gigabit SFP port. SFP port for pluggable 1000Base-LX optical or 1000Base-T electrical options.

8 ODU Status LED LED provides indications of:

Off IDU power off

Green Normal operation

Orange flashing Configuration not supported, software/hardware incompatible, or diagnostic mode selected, such as Tx Mute.

Red Critical alarm (traffic affecting)

IDU Status LED LED provides indications of:

Off IDU power off

Green Normal operation

Orange flashing Configuration not supported or software/ hardware incompatible, or diagnostic mode selected, such as tributary loopbacks.

Red Critical alarm (traffic affecting)

9 Alarm I/O HD-15 connector provides access to two TTL alarm inputs and four form C relay


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outputs. Connections are mapped in Portal.

10 NMS 10/100Base-T RJ-45 connector assembly provides two ports for Ethernet network management access. Unless DHCP has been configured, Portal login requires entry of a LAN compatible IP address on your PC. Second port provides NMS connectivity to co-located Harris Stratex or third party radios. The orange connection-status LED is on for a valid Ethernet connection. Off indicates no connection or an invalid connection. The green activity LED flashes to indicate Ethernet traffic on the port. The LED does not flash (is solid on) when there is no traffic activity. (Activity LED is off when the connection status LED is off).

11 Protection Provides bus interconnection between protected IDUs (hot-standby or space diversity). Tx switching is not hitless, Rx path switching (voting) is hitless. Tx/Rx online and primary/secondary status is indicated by the protection connector LEDs as: Green Online LED is on for an online Tx and/or Rx. (Normally the online IDU is

online for both Tx and Rx). Green Online LED is off for the offline IDU (IDU is not transmitting or controlling

Rx diversity operation (driving the tribs). Orange Primary LED is on for the primary IDU. (The primary designated IDU is

default online for Tx and Rx). Orange Primary LED is off for the secondary IDU.

11 Maint V.24 RJ-45 connector provides a V.24 serial interface option for Portal. It supports a default IP address, which means knowledge of the Terminal IP address is not required at login.

Link Aggregation IDU GE 20x link aggregation conforms to IEEE 802.3ad. It is enabled in the DAC GE module.

This feature is scheduled for future release. Check availability with Harris Stratex or your supplier.

Link aggregation combines two or more links into a single logical link, with a traffic capacity that is the sum of the individual links.

It is especially relevant to digital microwave links where two co-path links are needed to provide the required link capacity.

Radio modulation techniques typically restrict data maximums to about 360 Mbit/s per link for a maximum-sized 56 MHz RF channel, or to 200 Mbit/s for a 28 MHz channel. Using 56 MHz channels, two physical links would be required for 600 Mbit/s, three when using 28 MHz channels.

28 MHz channels are generally supported on all frequency bands, whereas the 56 MHz channels are mostly restricted to bands 18 GHz and higher.

Figure 9 shows link-aggregated 360 Mbit/s IDUs operating on adjacent 56 MHz channels to provide a 720 Mbits logical link connection. Similarly, link aggregated 200 Mbit/s IDUs on adjacent 28 MHz channels provide a 400 Mbit/s connection.

Note that the co-path links do not need to be operated in the same RF band. If on different bands, separate band-specific antennas are required for each link.


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Figure 9. Link Aggregated Terminal for 720 Mbit/s

Link aggregation also provides redundancy on the physical links. If a link fails, its traffic is redirected to the remaining link, or links. If the remaining link(s) do not have the capacity needed to avoid a traffic bottleneck, QoS settings are used to ensure all higher priority traffic continues to get through.

Traffic from the failed link is typically recovered within 20ms. Traffic on the remaining link is unaffected, except where low priority traffic is

discarded as a result of a traffic bottleneck.

Traffic streams transiting the logical link are split between the physical links based on their source and destination MAC addresses and the aggregation key allocated to each of the physical links comprising the link aggregation group. This splitting prevents the occurrence of an IP loop, even though all traffic is sent and received on a common LAN interface at each end of the logical link.

A session is established between source and destination MAC addresses. Once established, all traffic will use the established link, which will be over one radio link, or the other it cannot be split over both.

An aggregation key process sets the weighting (load balancing) of traffic between the links in the aggregated group, where the number of keys assigned to each physical link port is based on the split of capacity between the links. For example, if the aggregated group comprises two links of equal capacity, the keys are assigned equally. User traffic is allocated between the keys on a random basis.

With normal LAN traffic densities (20+ concurrent sessions), L2 aggregation keying generally ensures equitable balancing of traffic between the links. However, where there is only a single MAC address in play, such as a connection between two routers, L2 link aggregation is not effective. It can also be sub-optimal where there are only a few active data streams and there is a significant imbalance between the bandwidth demands of each stream.

Identical link capacities are normally configured, though this is not a requirement. For example, a 360 Mbit/s link can be link aggregated with a 150 Mbit/s link to support a 510Mbit/s logical link.


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RWPR The RWPRTM (Resilient Wireless Packet Ring) capability enhances industry-standard RSTP to provide superior network reconvergence (service restoration) times on GigE ring networks. This is achieved through unique rapid-failure-detection (RFD) and dynamic message timing mechanisms:

Eclipse RFD detects any link failure and instantly shuts down the Ethernet ports at both ends of the link. This is detected on the ports of the co-located IDU GE 20x terminals to directly initiate RSTP reconvergence.

Dynamic message timing is used to accelerate the RSTP reconvergence process.

The resulting reconvergence times are typically less than 1 second. This represents a major improvement over the 7+ second times of links that simply rely on the aging out of keep-alive messages to signal a link failure.

RWPR delivers reliable and consistent RSTP operation, even in the presence of link fading. It is a Harris Stratex Networks development, and a patent is pending.

Link Protection Hot-standby or space diversity protection is configured using two IDU GE 20xs with companion ODUs. RJ-45 cables inter-connect the IDUs to enable protection and to link the NMS and L2 switch functions. The protected configuration protects both the Ethernet and NxE1 traffic.

Path / Rx protection is hitless. Both receivers are online, and at any instant in time the least errored payload stream is used to provide the output.

Ethernet Protection The three Ethernet operational modes of Transparent, Mixed and VLAN are used to support protected operation, though in a bridged format for Mixed and VLAN modes. This is illustrated in Figure 10, and in the following Portal screen extracts for each protected mode; Figures 11, 12 and 13.

When protected, both Primary and Secondary IDUs are configured to use the same Ethernet mode, and the same mode is selected at the far end of the link. All modes require an Ethernet cable between Port 2 of the co-located IDUs.

The resulting protection fully protects Ethernet traffic over the link and partially protects1 the Ethernet interface.

1 The interface is not protected if one of the IDUs is removed or powered-down. Any Ethernet traffic connected via that IDU will be lost.


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Figure 10. IDU GE 20x Ethernet Protected Operational Modes

Protected Transparent Mode Traffic is transported on C1 or C2. All ports, Primary P1 and P4 and Secondary P1 and P4, are connected together and to C1 and C2. To avoid an Ethernet loop over the link, only C1 or C2 is mapped to the radio module. Figure 11. Protected Transparent Mode Diagram

Protected Bridged Mixed VLAN Mode Traffic is transported as two independent VLANs on C1. Primary P1 and Secondary P1 are connected together and transported as a VLAN. Similarly, Primary P4 and Secondary P4 are transported as a VLAN. Figure 12. Protected Bridged Mixed VLAN Mode Diagram

Protected Bridged VLAN Mode Traffic is transported as two independent streams, one on C1, the other on C2. Primary P1 and Secondary P1 are connected together and transported on C1. Similarly, Primary P4 and Secondary P4 are connected together and transported on C2.

Compared to the Protected Bridged Mixed VLAN mode, this mode ensures that the bandwidth (capacity) assigned to each VLAN is held separate from the other.


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Figure 13. Protected Bridged VLAN Mode Diagram

Protection Switching Behavior Both Ethernet Tx and Rx are switched in the event of an Ethernet switch.

An IDU online Tx switch causes an Ethernet switch, which means that:

Ethernet Tx is disrupted for not more than 400 ms; typically less than 300 ms.

Ethernet Rx is disrupted for not more than 200 ms; typically less than 100 ms.

An IDU online Rx switch does not cause an Ethernet switch, therefore Ethernet traffic is not affected.

A failure in the Ethernet switch of one IDU will not cause an IDU online Tx or online Rx switch.

E1 Trib Port Protection The E1 tribs and interfaces are fully protected. Y cables are used to provide electrical or optical trib split/merge.

Network Applications The IDU GE 20x was designed for high speed Ethernet connections, with or without wayside TDM traffic. Primary applications include mobile and WiMAX network backhaul, and high speed service provider network connections.

This section illustrates typical applications for:

Broadband Backhaul Edge Terminals in an INU Network GigE Inter-Site Company Network Connection: Example No. 1 GigE Inter-Site Company Network Connection: Example No. 2 Metro Edge Switch

Broadband Backhaul Figure 14 shows a backhaul network using radio and fiber rings to the core. While a WiMAX application is shown with WiFi at some network ends, the solution also applies to cellular or other broadband networks.

The application shows: IDU GE 20x used as a cost efficient backhaul solution for WiMAX base stations.

- WiMAX products generally support up to about 20 Mbit/s per sector for a four-sector base station. On short hops higher modulation rates are used to support higher capacities when needed. On long hops, +20 km / +12 miles, system gain implications may require the use of lower-order modulation with capacities restricted to not more than 1.5/2 Mbit/s.

- WiMAX in-band backhaul does not scale well; when the network grows it soon runs out of capacity / RF bandwidth.


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- IDU GE 20x on the other hand provides dedicated GigE connectivity, and links can be cost-efficiently engineered to support capacity maximums on both short and long line-of-site distances.

IDU GE 20x links used as cost efficient GigE fiber ring closures on 1Gb and 500 Mbit/s rings.

On the 1 Gbit/s ring two IDU GE 20x links provide a 720 Mbit/s closure. In this example, where the total IDU GE link capacity is less than the nominal ring capacity, RSTP switch settings may be configured so that traffic does not traverse the IDU GE 20x link, unless there is a failure in one of the fiber links. - When a fiber link fails, traffic up to the break point going via the IDU GE 20x

links is restricted to a maximum 720 Mbit/s. Traffic traversing the ring to the other side of the break retains a 1 Gbit/s maximum.

- The IDU GE 20x links may be operated as two independent 360 Mbit/s links, with link aggregation set in the attached L2 switches, or the built-in link aggregation option can be used to present a single 720 Mbit/s logical link interface.

- The two co-path links are operated on adjacent 56 MHz RF channels using a single dual polarized antenna at each end.

- This example represents an effective and cost-efficient use of a radio closure.

Similarly, a single 360 Mbit/s IDU GE 20x link is used as a closure on a 500 Mbit/s fiber ring.

A 360 Mbit/s enhanced-RSTP ring is directly supported from IDU GE 20x links using its RWPR settings. External RSTP switches are not required.

A single 60 Mbit/s IDU GE 20x link is used to close a ring established on the WiMax base stations.

Benefits include: IDU GE 20x provides a compelling alternative to the use of WiMAX base stations

for backhaul, especially on longer hops and towards the core where a higher proportion of the data carried is backhaul. The IDU GE 20x offers a dedicated, lower cost solution and does so with flexible expansion options.

Up to 360 Mbit/s can be transported over one IDU GE 20x link. Capacity options range from as low as 10 Mbit/s.

Where path and/or equipment protection is required, two co-located IDU GE 20x terminals are configured for space diversity or hot-standby operation. The bridged switch options provide a single Ethernet user interface.

An IDU GE 20x link can be up and running in a fraction of the time and cost of installing fiber.


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Figure 14. WiMAX Backhaul Example

Edge Terminals in an INU Backhaul Network Figure 15 shows IDU GE 20x terminals linking to INUs within a mobile backhaul network. The INUs are shown in a 150 Mbit/s / 75xE1 tree topology, or RWPR / PDH ring topology.

Spur links from the INUs are installed using IDU GE 20x terminals at the remote sites.

Traffic is Ethernet and E1. Or the traffic may be all NxE1, but the network is required to be Ethernet-ready.

The application shows: IDU GE 20x air-compatibility with an INU fitted with a RAC 30 or RAC 3X.

- RAC 30 compatible capacities range from 10 Mbit/s in a 3.5 MHz channel, to 150 Mbit/s in a 28 MHz channel. (RAC 30v3 or RAC 30v2+)

- RAC 3X compatible capacities are 130 or 200 Mbit/s in a 28 MHz channel, 200 Mbit/s in a 40 MHz channel, or 150 or 200 Mbit/s in a 56 MHz channel.

IDU GE 20x payload compatibility with an INU for Ethernet and E1 tribs. - Ethernet capacity is terminated on a DAC GE or DAC ES card in the INU. - E1 tribs are terminated on a DAC 16x or DAC 4x card in the INU.


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IDU GE 20x Alarm I/O compatibility with an INU. IDU GE 20x support for Ethernet and/or E1 payloads. E1 up to 20xE1.

IDU GE 20x is also air-compatible with the IDU ES for Ethernet throughputs to 100 Mbit/s, and the IDU 20x for 5xE1 to 20xE1.

Benefits Include:

Lower cost. The IDU GE 20x is a low cost solution for a GigE-plus-E1s terminal. Similarly, the INU is the lowest cost solution for nodal applications. Together they provide a particularly efficient and cost optimized wireless solution for Ethernet networks, or Ethernet-and PDH networks.

Easy migration to Ethernet. Provides future-proofing for the expected migration from all-PDH to PDH+Ethernet, and ultimately to all-Ethernet. Both the IDU GE 20x and INU are ideal platforms for migration to Ethernet. For the IDU GE 20x, this Ethernet/PDH flexibility is built-in. For the INUs, enabling Ethernet is simply a case of fitting a DAC GE or DAC ES card.

Figure 15. IDU GE 20x as an Edge Terminal in an INU Network

GigE Inter-Site Company Network Connection: Example No. 1 Figure 16 illustrates a protected IDU GE 20x link between two company sites. All data and voice services for the Main and Satellite sites are ported to external networks via the main site.

The application shows: A protected IDU GE 20x link installation. Hot-standby is shown; space diversity is

also available. The protected configuration provides the added resilience needed to provide peace-of-mind. Providing the path is correctly engineered for the expected path variables (rain, ducting, reflections), overall reliability will be at least as good as a fiber connection. Path receiver switching is hitless (errorless).

A single Ethernet interface (multiple ports) is provided on the protected link. Where multiple ports are used, traffic can be transported within one link-channel, or within two (bridged VLAN Mode), where bandwidth for each is held separate from the other. Should the available bandwidth be insufficient for peak bursts, port and CoS prioritization options can be configured to ensure all higher priority traffic is unaffected.

All inter-site data and voice is carried on the protected link. Legacy PBX trunks are E1 connected. Options include operating an Ethernet-

only link and using VoIP-capable PBX trunk connections. Link capacities range from 10 to 360 Mbit/s.


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Benefits include: Cost savings by bypassing the need for data and PBX service provider

connections between the sites. - A check against inter-site lease rates should show break-even on a

protected link occurring within one to three years, with significant savings thereafter.

- A check against rates for maintaining separate Internet, Intranet, and PBX connections for each site should show even greater cost savings.

Guaranteed access to bandwidth. The capacity on the link is dedicated to company use. It may be managed by the owners or installed and contract-managed by a local services company. Owners have full control of service delivery and service quality.

Figure 16. Inter-Site Hot-Standby or Space Diversity IDU GE 20x Link

GigE Inter-Site Company Network Connection: Example No. 2 Figure 17 illustrates a situation where a company prefers to stay with an existing service provider for inter-site data and voice services, but wishes deliver additional capacity by installing their own GigE link. The link is required to operate with the service provider connection in a link-aggregated or RSTP configuration.

The application shows:

Existing network connections provided by a service provider. An IDU GE 20x link installed to provide up to 360 Mbit/s Ethernet plus E1 PBX

trunk connections. Network capacity.

- Link Aggregation option: The total Ethernet connection capacity is the sum of the service provider and IDU GE 20x capacities.

- RSTP option: The connection capacity is the IDU GE 20x capacity. The service provider connection serves only to provide redundancy.

- The link aggregation or RSTP functions are enabled on the external L3 switches.

Network redundancy. - Link Aggregation: The IDU GE 20x link is incorporated within a link-

aggregated group comprising the IDU GE 20x and the service-provider link. If one of the two traffic paths fails, traffic from the failed path is redirected to the remaining path. Traffic prioritization (VLAN priority tagging) is used to ensure all essential traffic continues to get through should the reduced bandwidth result in a bottleneck.

- RSTP: The IDU GE 20x is a link in an RSTP mesh network comprising the service provider paths and the IDU GE 20x. If the IDU GE 20x link fails,


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traffic prioritization (VLAN priority tagging) is used to ensure all essential traffic continues to get through on the lower-capacity service provider connection.

- Legacy PBX trunk connections can be maintained using the NxE1 tribs on the IDU GE 20x, with redundancy supported on the Ethernet network using a VoIP interface. Alternately, all trunks can be VoIP.

- Network redundancy is provided door-to-door. While the service provider network should have built-in redundancy, this usually does not cover last mile connections.

VLANS are used to support different company user groups within the company, such as R&D, Finance, and Sales, to support optimum workgroup management, security, and traffic control.

All external Internet and phone portals are provided through the Main site, to avoid the cost of maintaining separate external network connections to both sites.

Benefits include: Cost savings. The additional capacity is provided in-house, thereby eliminating

the cost of an extended-capacity lease rate from the service provider. Break-even on the installation of the IDU GE 20x link should occur within one to two years. And by removing the need to maintain separate external Internet and PBX services to both, even greater savings are possible.

Reliability. The link-aggregated or RSTP network provides traffic redundancy right to the companys premises.

Guaranteed access to bandwidth. All bandwidth on the IDU GE 20x link is dedicated to company use.

Figure 17. Inter-Site Link Aggregated or RSTP Application

Metro Edge Switch Figure 18 shows two IDU GE 20x link-aggregated links providing an edge function in a metro network.

The application shows: Co-located 360 Mbit/s IDU GE 20x links providing a 720 Mbit/s logical link. If one of the links fails a 360 Mbit/s connection is maintained. A similar level of

redundancy could be provided using a hot-standby link pairing, but maximum throughput would be fixed at 360 Mbit/s; aggregation allows you to capitalize on what would otherwise have been standby capacity.

At the office site, customer VLANs are aggregated (VLAN aggregated) onto the 720 Mbit/s link. Customer VLANs are tagged (double tagged) using IDU GE 20x Q-in-Q VLAN tagging. The tagging includes an 802.1p priority classifier.

At the core end of the link, the IDU GE 20x Q-in-Q tagging can be stripped off, or maintained into the core network for downstream management purposes.


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If additional protection (redundancy) is required, one or both links can be hot-standby or diversity protected.

Benefits include: Tandem link-aggregated IDU GE 20x links deliver reliable, high-capacity, and

cost-effective connections. A scaled approach to required IP bandwidth. One IDU GE 20x link can be used to

deliver capacities from 10 to 360 Mbit/s. When more capacity is needed, an additional link is added to provide up to 720 Mbit/s on a common user interface.

Built-in Q-in-Q VLAN tagging. The IDU GE 20x links can be fully integrated into the service provider VLAN hierarchy. Customer VLANs are held separate from the service provider VLANs.

Customer VLANs can be prioritized to provide a differentiated service over the wireless VLAN trunk. This has application in the provisioning of service level agreements (SLAs).

Figure 18. Metro Network Edge Link

Summary The IDU GE 20x combines high capacity, outstanding flexibility, and low cost to provide exceptional performance options for wireless network connections. It is particularly applicable to:

Point-to-point 1+0 and 1+1 links for capacities from 10 to 360 Mbit/s Ethernet, with or without companion E1 circuits.

Link aggregation, where two or more point-to-point links are needed to provide capacities greater than 360 Mbit/s. Two IDU GE 20x links provide an aggregate capacity to 720 Mbit/s, with each link providing traffic redundancy for the other.

Use in backhaul networks where migration from PDH to Ethernet is required now, or in the future. Up to 20xE1 circuits can be configured at the outset, plus Ethernet up to 300+ Mbit/s.

RSTP operation. The built-in PWPR capability delivers sub-second reconvergence times.

Installation as cost-efficient edge terminals in an INU nodal network, using the air and payload interoperability between the INU and IDU GE 20x.



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Glossary 802.1d IEEE standard for spanning tree. 802.1d-2004 defines the current RSTP

iteration.

802.1p IEEE standard for QoS traffic prioritization using three bits in the CoS header (defined in 802.1q) to allow switches to reorder frames based on priority level.

802.1Q IEEE standard for virtual LAN (VLAN) identification and QoS levels. Three bits are used to allow eight priority levels, and 12 bits are used to identify up to 4,096 VLANs.

802.3ad IEEE standard for layer 2 link aggregation.

CoS Class of service; a layer 2 header in an Ethernet frame. Frames are tagged, either at the originating device or at an intermediate point, to identify a requested level of service.

DiffServ Differentiated services code point (DSCP). A field in an IP header which can be used to tag a packet, either at the originating device or at an intermediate point, to identify a requested level of service.

FPGA Field-programmable gate array.

RFD Rapid failure detection.

MAC Media access control.

MTU Maximum transmission unit.

NTU Network terminating unit.

PDH Pleisiochronous digital hierarchy. Asynchronous multiplexing scheme in which multiple digital synchronous circuits run at slightly different clock rates.

PHY Physical, layer 1 level/interface.

QoS Quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability.

RSTP Rapid spanning tree protocol.

RWPRTM Resilient Wireless Packet Ring

SLA Service level agreement

SFP Small-form-factor pluggable.

STP Spanning tree protocol.

TDM Time division multiplexing. Multiple low-speed signals are multiplexed to/from a high-speed channel with each signal assigned a fixed time slot in a fixed rotation.

VLAN Virtual LAN. IEEE 802.1Q tagging mechanism.

WiFi Acronym for Wireless Fidelity. WiFi is a trademark of The Wi-Fi Alliance (www.wi-fi.org).

WiMAX Acronym for Worldwide Interoperability for Microwave Access. Interoperability brand behind the IEEE 802.16 Metropolitan Area Network standards.

IDU GE 20xContentsIntroduction to IDU GE 20xCapacity and Bandwidth OptionsIDU GE 20x CompatibilityDAC GE ModuleEthernet Modes of OperationTransport ChannelsBasic Ethernet Port SettingsPriority MappingFlow ControlDisable Address LearningMaximum Frame SizeLink Status PropagationVLAN TaggingEthernet Diagnostics

Wayside Traffic ModuleAlarm I/O ModuleIDU GE 20x LayoutLink AggregationRWPRLink ProtectionEthernet ProtectionProtection Switching BehaviorE1 Trib Port Protection

Network ApplicationsBroadband BackhaulEdge Terminals in an INU Backhaul NetworkGigE Inter-Site Company Network Connection: Example No. 1GigE Inter-Site Company Network Connection: Example No. 2Metro Edge Switch

SummaryGlossary

Eclipse IDU GE 20x White Paper ETSI

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