Computer System Networking and Telecommunications
Original Research Article
Application and Development of PTN Technology
Yang Zhang,Suqing Ye,Guowei Xu
Computer Information Institute, Yangzhou University of Science and Technology, Jiangsu, China
ABSTRACT
The packet transmission network (PTN) technology, which combines the advantages of packet technology and
synchronous digital system (SDH) technology, is more suitable for multi-service bearer and exchange, and satisfies
flexible network scheduling and multi-service transmission. It can provide network protection function. PTN technical
characteristics determine that he can better use the existing network, can provide more with the current network
interface. This paper analyzes the characteristics of PTN technology and the existing networking methods, and
proposes a network improvement method of IP + PON + PTN.
KEYWORDS: PTN; packet switching; main network mode
1. Introduction
PTN generation background operators have begun to enter the full business operation era. Full business
means integration, IP is the basis of integration. ALL IP has become the trend of today's business development. In the
traditional business IP at the same time, born with IP line of new business to flourish, and the current transmission
network and traditional data network by its technical system constraints, has become more and more business, network
IP development constraints, so, PTN Technology in this context came into being. After the issuance of domestic 3G
licenses, the three operators are in the transformation of IP. IP of mobile networks is more complex than IP for fixed
networks. The IP of the mobile network, in addition to the needs of the traditional business IP, but also on the clock,
network delay, reliability and security requirements are higher, so the bearer network has a new demand. The current
mobile IPRAN construction is a hot topic in the industry. The traditional MSTP transmission technology cannot meet the
long-term development requirements of mobile IP RAN in terms of load efficiency, scalability and cost. It needs a new
packet-based technology to replace MSTP, PTN The emergence of just to adapt to this demand. As the needs of IP RAN
integration of transmission and data technology features, in the solution also reflects the diversity, in addition to PTN
technology, there are MSTP PTN transformation, router enhancement program. According to ZTE PTN domestic market
director Wang Yang introduced the traditional SDH and routers through the transformation is difficult to meet the longterm development needs of operators, although MSTP can meet the initial needs of 3G, but in the late 3G will be lack of
power, while operators in the 3G later there is a large number of carrier transport network investment, MSTP life cycle
is not very long, and operators need to be able to support long-term business development of the network, operators of
mobile broadband and wireless broadband Internet development, mobile bearer transmission needs The amount is also
very large. In her view, through the MSTP transformation or router transformation to achieve the carrying IP business,
will need a certain period of time to meet the functional requirements of the operator's time window is relatively
backward, not suitable for long-term development and long-term investment plan. And PTN from the beginning is
committed to meet the long-term needs of operators starting. With the large-scale deployment of 3G networks to meet
the underlying 3G network transmission needs is imperative. The existing SDH / MSTP / ASON transmission network
is less efficient than IP, which is less efficient when carrying IP service. In order to meet the needs of future network
development and network convergence, PTN (MPLS-TP) technology is adopted to enhance Ethernet technology and IP
/ MPLS and other technologies to conduct a unified business IP unified carrying a variety of technologies which came
into being.
Copyright © 2017 -. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International
License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all non-commercial use, distribution, and reproduction in any medium, provided
the original work is properly cited.
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2. Introduction to PTN
2.1.
PTN definition
PTN (Packet Transport Network) packet transmission network, is the industry in order to be able to more
effectively in the transport layer to pass packet services, and provide carrier-class OAM and protection of a packet
transmission technology. There are two types of PTN packet transmission: one is based on Ethernet technology PBBTE (Provider Backbone Bridge - Traffic Engineering), mainly developed by the IEEE; the other is based on MPLS
technology T-MPLS / MPLS-TP, jointly developed by ITU-T and IETF. However, with the decline of Nortel, T-MPLS
/ MPLS-TP has become the only mainstream technology of PTN in the transmission layer, and has been deployed in
China Mobile Metropolitan Area.
2.2PTN main features:
1) Using the same hierarchical network architecture as existing local transport networks.
2) The access layer adopts the ring or chain structure network, and the client side adopts E1 and FE ports.
3) Aggregation layer and above can be used ring or MESH network, can be carried on the WDM system; upper and
lower layers can be connected with two access methods.
4) Aggregation layer and above with large capacity 10G line side port.
5) Can support a variety of access business types.
6) Can achieve rapid deployment, to adapt to environmental capacity stronger.
2.3. PTN's main advantages:
1) Innovative high-performance carrier-class packet architecture to achieve from the data network to the
telecommunications network across.
2) End-to-end QoS design provides fine bearer and improved grading quality assurance. Adopting SDH-Like OAM \
u0026 P is the most critical improvement in carrier-class capability for packet networks.
3) PTN adopts pipelined transmission idea, which can realize the various functions defined by DiffServ (traffic
classification, traffic policing, congestion management, queue scheduling and Shaping) according to MPLS forwarding
mechanism. The business bandwidth and performance Qos indicators.
4) Within the city to provide less than 50ms of business protection time.
5) Inherited SDH end-to-end management capabilities to make IP networks for the first time with manageable, easy
to maintain the attributes.
PTN technology is mainly located in the high reliability, small particles of business access and bearing the
scene, mainly used in metropolitan area network at all levels of business and network level, to provide E1, FE, GE,
10GE bandwidth particles, but because of its processing The kernel is a grouping method, so the bearing capacity of the
packet service is large, and the capability of carrying the TDM service is limited.
In the metropolitan area network of China's operators, PTN technology is mainly located in the metropolitan
area of the convergence of access layer to address the following needs: 1) multi-service bearer: wireless base station
return TDM / ATM and future Ethernet business, enterprises And the home user's Ethernet business; 2) business model:
metro traffic flows from the business access node to the core / convergence layer of business control and switching
nodes, point to point (P2P) and point to multipoint 3) Strict QOS: TDM / ATM and high-level data services require
low latency, low jitter and bandwidth guarantee, while broadband data traffic peak traffic is large, and high-level data
services are required. 4) Carrier-class reliability: the need for reliable, connection-oriented carrier-class bearer, providing
end-to-end OAM capabilities and networks, and the ability to provide end-to-end OAM capabilities and networks with
strong connectivity, bandwidth management, priority scheduling and congestion control; Fast protection capacity; 5)
network cost control and scalability: many large and medium-sized cities in China have thousands of business access
points and hundreds of business convergence section Point so that the network requires low cost, unified management
and maintainability, while in the metropolitan area within the business distribution and extensive, requires a strong
network scalability.
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Application and Development of PTN Technology
3.
PTN implementation technology
3.1. Transmission of Multiprotocol Label Switching (MPLS-TP) technology
Transmission of Multiprotocol Label Switching (MPLS-TP) technology from Internet Protocol / Multiprotocol
Label Switching (IP / MPLS). The technology eliminates the hop-by-hop forwarding mechanism based on IP addresses
and relies on the control plane to establish the transport path; preserves the multi-protocol label switching (MPLS)
connection-oriented end-to-end tag forwarding capability; Non-end-to-end features that do not use the last-hop pop-up
(PHP), tagged path merging and equivalent multipath, thus having a definite end-to-end transport path and enhanced to
meet the transport network requirements; Style of network protection mechanisms and OAM capabilities.
3.2. Connection-oriented Ethernet transmission technology
Connection-oriented Ethernet delivery technology developed from Ethernet, such as the IEEE backbone of the
IEEE 802.1Qay specification - Traffic Engineering (PBB-TE). This technology has been improved on the basis of IEEE
802.1ah operator backbone bridging (PBB, MAC in MAC), eliminating the need for Ethernet connectionless learning,
spanning tree and flooding, such as media access control (MAC) Traffic Engineering (TE) to enhance QoS capabilities.
PBB-TE currently supports point-to-point and point-to-multipoint connection-oriented service delivery and linear
protection, and does not support connection-oriented multipoint-to-multipoint traffic transmission and ring protection.
3.3.
PTN support for L3 functions and services
The current PTN is mainly located in the provision of Layer 2 (L2) services, including E1 / ATM simulation
services, E-Line / E-LAN / E-Tree Ethernet services. PTN's main application scenario is the return of mobile networks,
including the current 3G network, and the future of long-term evolution (LTE). PTN can well meet the needs of existing
3G network backhaul, but it is also doubtful whether it can meet the needs of LTE.
L3 functions include IP routing and forwarding functions, and L3 MPLS VPN and L3 multicast functions.
Because of the flow bandwidth and routing uncertainty of IP traffic and multicast, it is difficult to provide strict QoS
guarantee capability. If these two services are introduced into the PTN, the two services can only be set to the lowest
level of service in order to avoid the impact on the original L2 service. The L3 MPLS virtual private network (VPN) is
based on MPLS implementation, so you can use MPLS-based traffic engineering and differentiated service mechanisms
to protect the quality of service services. But also can support L3 multicast in MPLS VPN, also can guarantee the
quality of service.
3.4.
Data plane loopback function
Existing PTN devices only support OAM loopback (LB). OAM LB can verify the two-way connectivity
between the source and sink to detect inter-node and node faults, but it cannot locate the fault accurately. As shown in
Figure 1, if the link between PE2 and PE3 fails, it cannot be determined whether the PE3 fails or the link between PE2
and PE3 fails through OAM LB. If you support SDH equipment like data plane loopback, that is, business loopback,
you can loop through the different points to achieve the exact location of the fault.
Similar to SDH, the data plane loopback of the proposed PTN includes three modes: remote loopback
(loopback), near loopback (exit loopback), and fiber loopback (customer loopback). In addition to fault location, fiber
loopback can also perform single-ended service performance testing, such as bidirectional delay, packet loss and
throughput testing, to facilitate the current network test.
4. Planning of PTN Network
IETF RFC5654 divides MPLS-TP into transport service layer, transport channel layer and segment layer.
Where the transport service layer may be a PW or a service LSP, similar to VC-12 in a synchronous digital system
(SDH) network. PW is used to provide simulation services such as time division multiplexing (TDM), Ethernet and
asynchronous transmission mode (ATM). The service LSP is used to provide network layer services such as IP and
MPLS. The transport channel layer refers to the LSP layer, similar to VC-4 in the SDH network. The segment layer
is used to aggregate the information of the transport service layer or the transport channel layer between two adjacent
MPLS-TP nodes. The segment layer can be implemented using MPLS-TP technology, or it can be implemented using
other technologies such as synchronous digital system / Ethernet / optical transport network (SDH / ETH / OTN). PTN
through the use of multi-layer network architecture, can be achieved with the synchronous digital system / optical
transport network similar scalability.
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In addition to MPLS-TP concerns 3-layer network, PTN equipment also need to support the business layer and
segment technology related functions. Such as Ethernet service layer OAM (belonging to IEEE802.1ag and Y.1731),
Ethernet link layer OAM (belonging to IEEE 802.3ah), SDH service and link overhead processing and protection
functions.
4.1.
PTN networking mode
PTN has the following technical characteristics:
1. Using packet-oriented packet switching (CO-PS) technology, based on packet switching kernel, support multiservice bearer.
2. Strictly oriented. The connection should be a long time, can be manually configured by the network management.
3. To provide a reliable network protection mechanism, and can be applied to the various network PTN network
layer and a variety of network topology.
4. For a variety of business to provide differentiated quality of service protection.
5. With perfect OAM fault management and performance management capabilities.
6. Packet forwarding based on tags. OAM packet encapsulation, transmission and processing do not depend on IP
encapsulation and IP processing. The protection mechanism does not depend on IP packets.
7. Supports bidirectional point-to-point routing and supports unidirectional point-to-multipoint routing; supports
traffic engineering control for point-to-point (P2P) and point-to-multipoint (P2MP) transport paths.
4.2. PTN network protection function requirements
PTN network support protection is divided into the following three categories:
(1) PTN network protection
Linear protection within the PTN network includes unidirectional / bidirectional 1 + 1 path protection, bidirectional 1:
1 or 1: N (N> 1) path protection, unidirectional / bidirectional 1 + 1 SNC / S protection and bidirectional 1 1 SNC / S
protection, should support at least two-way 1 1 protection mechanism.
PTN network ring protection, including Wrapping and STeering two protection mechanisms, should support at least
one ring network protection mechanism.
(2) Packet transmission network and other network access link protection
1. TDM / ATM access link 1 + 1 or 1: N protection.
2. Ethernet GE / 10GE access link protection, that is, link aggregation group (LAG).
(3) Double protection
PTN network protection and access link protection to achieve end-to-end service protection in the event of an access
link or PTN access node failure. Specific implementation mechanism to be studied.
PTN's network protection should meet the following general functional requirements:
(1) The protection switchover of PTN shall support the triggering of link, node fault and external command of
network management, and should support the priority processing of various switching requests. Fault type triggers
support for physical link, VP / VC signal failure (SF) and intermediate node failure, support signal degradation (SD).
The external command triggers support for network management commands such as locking to work, forced switching,
manual switching, and clearing commands.
(2) The protection switching mode includes support for single-ended switching and double-ended switching. It
supports the configuration of returning or not returning to the operating mode and supporting the start and wait recovery
times of the waiting for recovery (WTR) function.
(3) Protection switching time. When the delay time is set to 0, the service downtime caused by protection switching
should be no more than 50 ms (except for protection switching triggered by SD).
(4) Delay time setting. In the case where the underlying network of PTN (such as WDM and OTN) is configured
with protection mode, the PTN network protection mode should support the delay time setting, which can be set to 50
ms or 100 ms. 1.4 OAM architecture and functional requirements for PTN networks
The OAM function of the PTN network includes the OAM mechanism in the PTN network, the OAM
mechanism of the PTN network service layer, and the OAM mechanism of the access link layer. The OAM in the PTN
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Application and Development of PTN Technology
network is divided into alarm-related OAM, performance-related OAM and other OAM. Among them, the active OAM
refers to the periodic continuous implementation of the OAM operation. Proactively report fault and error performance
test results. On-demand OAM refers to a limited number of OAM operations initiated by the user, usually used for fault
diagnosis and positioning.
4.2.
PTN network level positioning
PTN inherits SDH / MSTP good networking, protection and operational capability, and uses IP core to provide
perfect flexibility bandwidth allocation, statistical multiplexing and differentiated service capabilities for Ethernet, TDM
and ATM. The business provides a rich client-side interface, ideal for high-level, small particle business flexible access,
convergence convergence and statistical reuse. The PTN can provide the maximum rate of network side interface only
10GE (Gigabit Ethernet) interface, with its formation above the backbone layer of the network is clearly unable to meet
the current business bandwidth explosive growth needs. Therefore, PTN is located in the metropolitan area convergence
access layer network, the future can be formed by the DWDM / OTN equipment with large bandwidth transmission
capacity of the metropolitan core backbone network and set up by the PON equipment focused on dense ordinary users
access Full service access network together constitute the main body of the metro transport network.
4.3.
PTN relationship with other networks
In the metropolitan area convergence access layer, China Mobile has been built or is the formation of SDH /
MSTP network, IP metropolitan area network and full service access network three networks, PTN network construction
will have on the existing network overlap or alternative What? From the network suitable for carrying the type of
business point of view, in the short term is not generated. SDH / MSTP network is suitable for carrying TDM services
and a small amount of high-level data services, IP MAN and full service access network in carrying ordinary data
services have a greater cost advantage, and PTN is suitable for carrying high-level data services and a small amount
TDM business, because the TDM business and service level differences in the data business needs within a short time
will not die, companies have further tap the current network potential to protect the needs of investment, so PTN will
coexist with the existing network, and common for the user Providing services that are more user-friendly in terms of
business type and safety level.
5.
The main application scenario of PTN
PTN equipment in the future of network applications is mainly in the metropolitan area network, mainly
mobile return, high-quality customer access and large customer virtual network.
PTN networking applications
On the basis of the existing network structure, the introduction of PTN equipment in metro transmission
network can be divided into PTN and SDH / MSTP independent networking, PTN and SDH / MSTP hybrid network
and PTN and IPoverWDM / OTN The In the mixed network mode, according to the IP packet service needs and
development, the introduction of PTN equipment can be divided into four evolution stages, the following were
introduced and analyzed.
5.1.
Mixed networking mode
Relying on the original MSTP network, from the business needs of the access point initiated by the SDH and PTN
hybrid group ring to the whole PTN group ring evolution model called hybrid network mode. The hybrid networking
model can be divided into four different phases.
Phase 1: In the early stage of base station IP and full service startup, the access layer has sporadic IP service
access demand. The introduction of PTN equipment mainly concentrates on the access layer and mixes with existing
SDH equipment to form SDH ring. , FE and other business access, taking into account the lack of access to IP business
needs, the stage above the convergence layer using MSTP network mode can still meet the demand.
Phase 2: With the deepening of the base station IP and the continuous promotion of the whole business, in the
business developed areas will be formed by the PTN alone built GE ring. Considering the requirement of connecting the
GE access ring at some convergence points, the nodes of the aggregation layer (such as nodes E and F) can be directly
replaced with PTN or MSTP by MSTP to upgrade to PTN devices so that such nodes have GE rings , But the entire
convergence layer is still MSTP network, access layer GE ring FE business needs in the convergence node E, F through
the business terminal board into E1 mode, and then through the convergence layer transmission.
Phase 3: In the outbreak period of IP service, the number of GE rings in the access layer is increasing, and the
packet transmission capability of the convergence layer is put forward higher requirements. In this phase, some nodes of
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Yang Zhang, et al
the convergence layer, such as B, E and F nodes, are superimposed on the MSTP loop, and then the GE / 10GE ring is
set up to meet the access and separation of the access layer TDM service and IP service.
Phase 4: After the development of the network, the whole network to achieve AllIP, the metro convergence
layer and access layer to form a complete PTN equipment to build the packet transmission network, network input and
output ratio greatly improved management and further simplification.
In the first three phases, the service configuration is similar to the 1 + 1PP mode of the SDH / MSTP network,
but only to the fourth phase of the pure PTN network. The configuration of the service is changed to the end-to-end 1:
1LSP mode. In general, the hybrid network facilitates the smooth evolution of the SDH / MSTP network to the whole
PTN, allowing the coexistence of different phases, different devices and different types of loops, and the investment is
carried out step by step. The risk is small, but at the beginning of the network evolution, in the network mode, because
the PTN device must take into account the SDH function, the transmission capacity of the network for the IP service
is limited and weakened, and the advantages of the PTN kernel cannot be exploited. In the late development of the
network, but also involves a large number of business cut, the pressure of network maintenance is very large. In view
of this, in addition to the lack of resources (such as local office room tension, power capacity is limited, cable routing
does not have the conditions) cannot meet the conditions for the formation of a separate PTN, or because of investment
restrictions must be implemented step by step PTN construction Do not recommend hybrid network mode for PTN
construction.
5.2.
Independent networking mode
From the access layer to the core layer all use PTN equipment, the new packet transmission plane, and the
existing network (MSTP) long-term coexistence, separate planning, common maintenance model called the independent
networking model. In this mode, the traditional 2G service continues to use the old MSTP plane, the new IP services
(including IP voice, IP data services) is open in the PTN. The network structure of the PTN independent networking
model is similar to that of the current 2GMSTP network. The GE group of the access layer and the convergence ring
are all 10 gigabit Ethernet rate group rings. The network is interconnected in the form of intersecting rings. as shown in
picture 1.
Independent network mode network structure is very clear, easy to manage and maintain, but the new
independent PTN one-time investment is large, need to take the node room valuable resources and fiber optic cable core,
power supply capacity of the bureau room need to power the transformation. In addition, SDH / MSTP equipment with
155Mbit / s, 622Mbit / s, 2.5Gbit / s, 10 Gbit / s multi-level line side of the network rate, from bottom to top multi-level
network structure, in contrast, PTN group Net rate is currently only GE and 10 Gigabit Ethernet two levels, if the use
of PTN to build more than two layers of multi-layer network structure, is bound to lead to one of the loop bandwidth
resources consumed too fast or a lot of idle problems, leading to the upper and lower network Rate mismatch.
At the same time, in the independent networking mode, the backbone layer nodes and the core layer nodes are
connected with 10 gigabit Ethernet loops. In the large metropolitan area network, the RNC nodes in the core layer are
more. On the one hand, the backbone nodes are connected with all RNC nodes , Loop node too much, the utilization rate
decreased, on the other hand, the loop on any node to increase the volume of business needs expansion, will inevitably
lead to the overall expansion of the loop, the network expansion costs are higher, so the independent network model
is more adaptable In the small number of core nodes within the small metropolitan area network set up two PTN, the
second is as IPoverWDM / OTN is not built and short-term cannot cover the transition network in place program.
5.3.
Joint networking mode
The following is the use of PTN networking, the core backbone layer is to make full use of IPoverWDM /
OTN uplink service scheduling to the PTN business floor room model known as the joint network. In this mode, after
the convergence layer is completed, the service is connected to the core room to set the large-capacity cross-landing
equipment at both ends and is connected with the RNC through the Trunk protection mode of GE optical port 1 + 1,
where the backbone node The PTN device is connected to the PTN crossover of the RNC node only through the GE
optical port, but not with the PTN crossover of the other RNC nodes and the backbone PTN device of the convergence
ring, as shown in Fig.2.
Although the PTN10 Gigabit Ethernet loop service formed by the core backbone layer in the independent
network mode can also be carried by the WDM platform, the WDM platform is only used as the bearer of the link. In
the joint networking mode, the IPoverWDM / OTN is not only Is only a kind of bearer means, and through the IP over
WDM / OTN on the backbone node of the GE business and its associated landing equipment between the scheduling,
the number of uplink GE channel can be based on the PTN in the actual access to the total number of business Ondemand configuration saves network investment. At the same time, because the backbone layer PTN equipment is
only associated with the RNC room, therefore, the joint network model is very suitable for multiple RNC room large
metropolitan area network, greatly simplifies the backbone node and the core node between the network formation,
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Application and Development of PTN Technology
Thus avoiding the PTN independent network mode, due to a node business capacity upgrade caused by the loop on all
nodes must be upgraded equipment, saving network investment.
Of course, the combined network of hierarchical network structure, the early investment will be due to
IPoverWDM / OTN construction and relatively high. In addition to the IPover WDM / OTN or short-term IP over WDM
/ OTN cannot cover the backbone of the convergence point of the area, in addition to the IPover WDM / OTN or shortterm IP over WDM / OTN cannot cover the backbone of the convergence point of the area, Are proposed to use a joint
network of metro metropolitan PTN construction.
PTN equipment set up a boutique network, mobile return in a certain period of time will only consume about
a few hundred megabytes of capacity, a large number of bandwidth can also be high for the network QoS requirements,
high reliability and high quality industry customers to provide access and Set up virtual network. As the industry's
proprietary network of customers is also the transition to IP, the introduction of PTN set up virtual network, can
be highly carrying, and bandwidth configuration can be very flexible, security and TDM networking as high, easy
management, more abundant means of maintenance.
PTN application scenarios include the use of existing networks and devices. PTN support for traditional
interfaces can provide uninterrupted service to the original service, use the old network to expand the coverage area
of the new network, the old network can also use the PTN features to further improve network performance and cost
benefits. To 2M business, for example, PTN 2M can still provide a reliable bandwidth guarantee, but when not in use
can be shared to other business, so the actual cost per megabyte bandwidth can be reduced a lot.
The introduction of new standard equipment often need to consider the relationship with the existing
equipment: is already with the existing equipment to form a hybrid network, or set up a separate network, whether
there is a better solution? China Mobile Zhejiang Branch has made in-depth analysis and comparison of the advantages
and disadvantages of various PTN networking models. Combined with the business characteristics of the province and
the future trend of technological evolution, the joint network model of OTN + PTN is put forward. As shown in Table
1, the SDH / MSTP + PTN hybrid networking mode and the PTN independent networking model will be frequently
adjusted or expanded due to network evolution requirements or resource bottlenecks. To adapt to the future business of
sudden strong, rapid growth in demand for bandwidth scenarios. The DWDM / OTN + PTN joint networking model has
a good network scalability, more suitable as a large-scale metropolitan area network such as Hangzhou mobile MAN
networking model.
PTN application scenarios can be extended to universal service. For small businesses, enjoy the green / private
service at the right price, enjoy high bandwidth and high reliability, not necessarily only use dial-up service. For general
personal users, unless the large capacity requirements, operators generally do not directly provide PTN services, more
likely to be a combination of PTN and access technology, by the PON and xDSL to provide home multi-service access,
and then spread to PTN The
5.4. PTN mainstream equipment
Huawei PTN3900 product specifications
Size (mm): 495 (W) x290 (D) x825 (H)
Suitable for ETSI 300/600 Rack (2.0m / 2.2m / 2.6m), 23inch open stand
Can provide 16 business processing slots, 16 interface slots
1 + 1 SCA / XCS / PIU protection, FANs redundant design
Smart E1: 1: N TPS
Exchange capacity (one way): 320Gbps
Standard power consumption: 900W
Interface Type
Smart E1 (IMA/ ML-PPP / TDM)
FE
GE
10GE
STM-1/4 POS
ATM STM-1
TDM STM-1
Interface Number / Board
32 (D75 / D12)
12 (ETFC),
16 (EG16), 2 (EFG2)
2 (EX2)
2 (POD41)
2 (AD1 / ASD1)
2 (CD1)
38
Interface Board Machine
504
188
160
16
32
144
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Yang Zhang, et al
Huawei PTN1900 product specifications
Size (mm): 436 (W) X258 (D) X220 (H)
Suitable for ETSI 300/600 rack (2.0m / 2.2m / 2.6m), 19inch cabinet, 19 / 23inch open stand.
Can provide two business processing slot (CXP), four business processing sub-card, five interface slots.
1 + 1 CXP Board protection
1 + 1 Power (PIU) protection, Fans redundancy
Smart E1: 1: 1 TPS
Exchange capacity: 10Gbps, can be extended to 40Gbps
Standard power consumption: 190W
Interface Type
Interface Number / Board
ML-PPP / TDM)
FE
GE
STM-1/4 POS
TDM STM-1
ATM STM-1
16 (L75 / L12)
12 (ETFC)
2 (EFG2)
2 (POD41)
2 (CD1)
2 (AD1)
Interface Board Machine Number of
interfaces
64
55
10
10
8
8
Huawei PTN950 product specifications
Size (mm): 442 (W) X220 (D) X88.1 (H)
Suitable for ETSI 300/600 rack (2.0m / 2.2m
/2.6m), 19inch cabinet, 19 / 23inch open stand
6 business processing slots
1 + 1 core switching / control / clock integrated processing unit redundancy protection
1 + 1 power supply, fan redundancy protection
Switching capacity: 8Gbps
Interface Type
Interface Number / Board
E1
CSTM-1
FE
GE
16 (L75 / L12)
1
8
2 (EG2)
Interface Board Machine Number of
interfaces
96
6
48
8
Huawei PTN910 product specifications
Size (mm): 42mm (W) X220mm (D) X44mm (H)
Suitable for ETSI 300/600 rack (2.0m / 2.2m
/2.6m), 19inch cabinet, 19 / 23inch open stand
2 business processing slots
1 + 1 power unit redundant backup
The main control board supports 16 * smart E1 (IMA / CES / ML-PPP) + 4 * FE (e)
Exchange capacity: 6.5Gbps
Interface Type
Interface Number / Board
E1
CSTM-1
FE
GE
16 (L75 / L12)
1
8
2 (EG2)
39
Interface Board Machine Number of
interfaces
48
2
20
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Application and Development of PTN Technology
ZTE PTN6100 product specifications
POWER: 1 power slot
FAN: embedded in the power board next to
Solt3: 1 motherboard slot
Solt1 ~ 2: 2 extended service slots
6. Development Trend of PTN
PTN technology is undoubtedly the peak of the current transmission technology development, it is following
the ATM attempt to unify the network world after the failure, it seems the most likely to achieve a unified network
technology. Network unified, the recent application of the goal is triple play, from the depth of technology, is through
the network of their own technological evolution, making the business itself as a service, more convenient for people,
people and machines, machines and machine communications The use of, rather than had to focus on the transmission
itself, in the future will have to achieve the network of self-organization, self-management.
PTN technology in 5 years will be large-scale deployment, as the mainstream of the transport network
equipment, PTN equipment may be more diverse forms. Such as the integration of access technology, and OTN,
ROADM technology integration. However, PTN provides one of the basic services of communication network, how to
apply convenience, efficiency, security and reliability, is still the constant pursuit of the goal.
The current multi-service service provided by PTN is mainly the transmission and interconnection of
homogeneous network. In principle, it can realize heterogeneous network interworking. The current PTN network is
mainly considered the possibility of large-scale deployment and reliability. The interoperability of the business data
level has been fully demonstrated, and the interoperability of UNI and ENNI interfaces at the control level needs further
study.
Transmission network Since the 80s of last century SDH production, its core technology has never been like
this, such a big change. PTN technology is so surprising that its emergence completely changed the location of TDM as
a core, replaced by packet switching and QoS support. It can fully accept all the important network that has appeared, it
completely maintains the core of the transport network technology, no doubt, PTN as SDH transport network successor,
in the network infrastructure services will play a cornerstone role.
References
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Huang Xiaoqing, Tang Jianfeng, Xu Rong, editors. PTN-IP packet transmission. Beijing University of Posts and
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