USOO7702762B1

(12) United States Patent (10) Patent No.: US 7,702,762 B1 Jagana (45) Date of Patent: Apr. 20, 2010

(54) SYSTEM FOR HOST TO-HOST 6,493.825 B1* 12/2002 Blumenau et al...... T13,168 CONNECTIVITY USING FICON PROTOCOL 6,499,058 B1* 12/2002 Hozumi ...... TO9,225 OVER A STORAGE AREANETWORK 6,636,529 B1 * 10/2003 Goodman et al. . ... 370/469 6,654,830 B1 * 1 1/2003 Taylor et al...... 71 Of 74 (75)75 Inventor: Venkata R. Jagana, Portland, OR (US) 6,658,5406,665,714 B1* 12/2003 SicolaBlumenau et al. et al...... 711,162709/222 (73) Assignee: states insists 6,714,9526,684,209 B2*B1 3/20041/2004 Ito(Shane et al...... at O'707:01 707/9 s s 6,718,347 B1 * 4/2004 Wilson ...... TO7,201 c - 6,728,803 B1 * 4/2004 Nelson et al...... T10/60 (*) Notice: Subject to any disclaimer, the term of this 6,769,021 B1* 7/2004 Bradley ...... TO9.220 patent is extended or adjusted under 35 2003/0236945 A1 12/2003 Nahum ...... 711 114 U.S.C. 154(b) by 2415 days. OTHER PUBLICATIONS (21) Appl. No.: 09/686,049 Computer Desktop Encyclopedia entry for "SAN” (copyright 1981 (22) Filed1C Oct.cl. 11,1 2000 2004), version 174, 4th Quarter 2004. * cited by examiner (51) Int. Cl. G06F 5/73 (2006.01) E. Early line Pich (52) U.S. Cl...... 709:23.700,246.700,249 (74) Attorney, Agent, or Firm Jason O. Piche 37Of 466 57 ABSTRACT (58) Field of Classification Search ...... 709/249, (57) 709/246 s 223,s 224,s 217 s 219; 370/465. 467 Th e invention comprisesp a SVy Stem for providinghproviding host-to-host h See application file for complete search history. connectivity through use of SAN. In the preferred embodi (56) References Cited ment, the end-to-end host connectivity is accomplished through the FICON protocol, over the Fiber Channel layered U.S. PATENT DOCUMENTS stack on a standard Fiber Channel adapter that runs transpar 5,867,648 A * 2, 1999 Foth et al...... TO9/230 ently across the SAN infrastructure. 6, 199,112 B1* 3/2001 Wilson ...... 709,227 6,400,730 B1* 6/2002 Latif et al...... 370/466 26 Claims, 8 Drawing Sheets

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17 U.S. Patent Apr. 20, 2010 Sheet 1 of 8 US 7,702.762 B1

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838. 3. U.S. Patent Apr. 20, 2010 Sheet 4 of 8 US 7,702,762 B1

Applications 31

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33 Emulation avers 34 ESCON Protocol Physical Fiber 35

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SCSI protocol 37

Fiber Channel 38 strack Physical Fiber -39

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FG. L. US 7,702,762 B1 1. 2 SYSTEM FOR HOST TO-HOST Area-Network) utilize configurations connected to PCs, serv CONNECTIVITY USING FICON PROTOCOL ers, print and storage devices, so too does FC. However, OVER A STORAGE AREANETWORK because FC uses fiber optic cabling, connections along a FC network are possible. Another feature of FC is its ability to BACKGROUND OF THE INVENTION provide increased bandwidth over communications channels. ESCON (Enterprise Systems Connection) is a fiber-based 1. Technical Field protocol. The ESCON protocol allows various emulations to This invention relates to network connectivity between run on top of it for further communication with the mainframe host computer systems over storage area networks (SANs) either directly or indirectly through ESCON emulators. How using the SAN's network protocol such as the FICON proto 10 ever, in order to perform this connectivity, the non-mainframe col. hosts need a separate ESCON hardware adapter, as well as 2. Description of the Prior Art other limitations. Network architecture is a blueprint that is used to guide the ESCON based physical channel speeds are 17 Mbps. design and implementation of networks. These blueprints are ESCON network connectivity is usually accomplished used because networks are not fixed at a single point in time, 15 through ESCON directors and hence the distances between but evolve to accommodate changes in both the underlying the end-hosts are limited. ESCON requires a repeater every technologies upon which they are based as well as changes in 1.86 miles. This requirement leads to increased costs when the demands placed on them. The primary function of a net the machines or hosts that are to be connected are far apart. work is to provide general cost-effective, robust and high By comparison, FICON (Fibre Connectivity) Channel is a performance connectivity among a large number of comput protocol that is targeted to provide high-speed storage Input/ CS. Output (I/O) capability. FICON provides a theoretical Channels and networks are the two primary ways that data throughput of 100 Mbytes/sec, which allows it to be used in a is transferred between devices such as processors, and periph SAN (Storage Area Network) environment. erals such as printers. Channels transfer data through Addressing the need for a centralized storage management Switched or direct point-to-point connections and they work 25 solution across heterogeneous networked resources, FC SAN by creating a fixed connection between the Source and desti architecture benefits a typical networked environment by nation devices until the transfer is complete. Channels trans delivering a dedicated storage environment, and by using of fer data at high speeds and are very economical. Networks, on high-speed fiber-optic or copper cabling to interconnect serv the other hand are collections of nodes Such as processors, ers, workstations and storage devices. print devices and workstations. Connections on networks are 30 As a data-channel network standard, the FC backbone of a slower than those made via channels. Channels work best SAN environment contains the network features that provide among few devices, and connect via predefined addresses. connectivity, distance and protocol multiplexing. Networks, on the other hand, can handle multiple requests Because FC SANs are protocol-independent, the support among multiple connections. Fibre Channel (FC) is a hybrid for network protocols like Tansmission Control Potocol/Iter of both network and channel methods and combines the best 35 net Potocol (TCP/IP) and audio/video is accomplished with a aspects of both. single physical layer. FC allows concurrent communication Host to host connectivity within a high-speed network among workstations, mainframes, servers, data storage sys environment is typically accomplished by using several dif tems and other peripherals using SCSI and IP protocols. The ferent types of network media. Network media include Token interconnectivity of computers and storage devices forms the Ring and Ethernet and other topologies. Token Ring is a 40 basis of a SAN. physical network technology in which hosts are connected in Although FC SAN is a fiber-based solution for high-speed a ring. A token (bit pattern) circulates around the ring and a storage access, there remains an industry need for high-speed, given node must possess the token before it is allowed to host to host connectivity that is an improvement upon the transmit. Token Ring has a bandwidth of 4 and 16 Mbps existing ESCON based architecture. (megabits per second). Fiber Distributed Data Interface 45 (FDDI) is a high-speed token ring networking technology SUMMARY OF THE INVENTION designed to run over optical fiber. The cables used for the token ring network are attached to adapters instead of the The invention comprises a system and method for provid hosts themselves. Ethernet is a network technology that uses ing host-to-host connectivity through use of SAN. In the CSMA/CD (Common Sense Multiple Access) and has a 50 bandwidth of 10Mbps or 100Mbps. The Ethernet protocol is preferred embodiment, the end-to-end host connectivity is implemented in hardware on the network adapter. accomplished through the FICON protocol, over the Fibre ASAN is a dedicated, centrally managed, secure informa Channel layered stack on a standard Fibre Channel adapter tion infrastructure which enables any-to-any interconnection that runs transparently across the SAN infrastructure. of servers and storage systems. SANS allows for connection 55 Other features and advantages of this invention will between storage devices and host machines across greater become apparent from the following detailed description of distances than are possible on a traditional local area network the presently preferred embodiment of the invention, taken in (LAN). SANs enable users to store large Volumes of data at conjunction with the accompanying drawings. remote locations called libraries. SANs are rapidly being BRIEF DESCRIPTION OF THE DRAWINGS integrated into distributed environments using Fibre Channel 60 technology. Fibre Channel (FC) is a high speed (1.06 Gbps) medium FIG. 1 is a diagram of a SAN connection according to the used for data transfer and storage. It is essentially a serial data prior art. channel created over fiber optic cabling. Fibre Channel pro FIG. 2 is a diagram of SNA & TCP/IP over SAN. vides a logical bi-directional, point to point connection 65 FIGS. 3 and 4 are diagrams of host-to-host connectivity between a host and a device. Just as existing networking according to the present invention. technologies using LAN/WAN (Local-Area-Network/Wide FIGS. 5-7 are block diagrams of prior art architecture. US 7,702,762 B1 3 4 FIGS. 8-9 are block diagrams of the architecture of the FIG. 4 is an example connection scheme that utilizes the present invention. present invention. The NT 21, Unix 22 and MVS 23 systems FIG. 10 is a schematic flow diagram of 3172 emulation are used in this example of the preferred embodiment. according to the present invention. Assume that the NT 21, UNIX 22 and MVS 23 systems are FIG. 11 is a CD-ROM bearing, a software embodiment of 5 connected to the SAN 25 fabric through a standard Fiber the invention. Channel connection. On the UNIX system side, a separate FC adapter is dedicated for the host connectivity in order to avoid DESCRIPTION OF THE PREFERRED the FC cable/port sharing with the storage I/O activity on this EMBODIMENT system. The FICON protocol 24 runs over the Fibre Channel 10 stack, and it is further required that it runs on both of these Overview system objects of interest. After the FC2 level connection is established, the FICON protocol then runs end-to-end Host-to-host connectivity through SAN offers several between these two systems, thus offering its services to the technological advantages over the prior art. The new archi emulation layers on top of it. These emulation layers further tecture is capable of higher bandwidths and, therefore, higher 15 provide the services to TCP/IP, SNA etc. which, ultimately speeds. There is no longer a need for new FICON hardware, service the applications. The layering architecture of the but rather the new architecture uses industry-proven FC hard present invention is explained in FIG. 8. ware. Hardware proofing cycles are eliminated, and there is In the preferred embodiment the SAN network is intended no device driver development required in the present inven not only to perform storage IO, but the SAN can also perform tion. Therefore, resulting in a significant reduction in the host-to-host network connectivity without interfering with development life-cycle of the product. The new architecture the storage IO activity. In the preferred embodiment the uses the existing emulation software layers and Fibre Channel FICON protocol runs transparently as far as the SAN is con stack, and the new architecture offers improved connectivity cerned, and therefore, the SAN is not aware of the type of at reduced costs. traffic that has been passing through. As shown in FIG. 3, the 25 primary purpose of the FICON protocol is to perform the Technical Background storage IO between the MVS systems and their storage sys tems, either directly or indirectly, through the SAN infra FIG.1 depicts the prior art connectivity that utilizes a SAN. structure at a much higher bandwidth than it is possible with Host A 1 is able to share data storage 6 with Host B2, which ESCON. could be a mainframe through the SAN5. Host A1 utilizes the 30 The network architecture of the present invention as shown SCSI protocol over FC 3 while communicating with SAN 5, in FIG. 8, provides a layered Stack concept logically extend while Host B2 utilizes the FICON protocol over FC 4. How ing the FC layered stack. The new network architecture is a ever, this configuration does not support direct Host A to Host combination of the architectures in FIGS. 5 and 7. The physi B communications. cal fiber 53 embodies the network hardware. The fiber chan 35 nel stack 52 is above the physical fiber. The FICON protocol The prior art network architecture that would support the 51 facilitates host communication with the SAN. The emula connection 3 between Host A 1 and the SAN 5 of FIG. 1 is depicted in FIG. 6. The physical fiber 39 are the cables pref tion layers 50 facilitate the imitation of other programs or erably fiber optic. The fibre channel stack 38 is a protocol devices. The protocol stacks 49 facilitate host-to-host com layered stack and SCSI 37 is a protocol layer on top of the munication and access to applications 48. 40 FIG. 9 is an example of the network architecture of the fibre channel stack. The Physical fiber and stacks provide the present invention. The FICON protocol 61 must run on top of means or channel for communications to the storage access the FC stack 62 which allows it to support different types of 36. emulation such as, 317257,3088 59 or 3174 60. Each emu The prior network configuration that would support direct lation supports its relative function, such as TCP/IP 56 or communications between two hosts is depicted in FIG. 2. In 45 high-speed file transfer application 55. After establishing a order for Host A8 to communicate directly with Host B9 in FICON level end-to-end connection, the respective emula either a local area network (LAN environment or wide-area tions on both sides can exchange the communication for network (WAN) and still maintain access with storage 12 further support of their service users. through the SAN 11. The SNA & TCP/IP protocol channel FIG. 10 is an example of how an emulation layer would 10. Host A8 and Host B9 are connected to storage 12 through 50 interface with the layer above and below it and in this the SAN 11. example, 3172 emulation is considered for a detailed expla FIG.7 depicts the architecture for both the SAN and LAN/ nation of how it works. The 3172 emulation layer 57 utilizes WAN networks. The architecture for the SAN utilizes the the FICON services at the lower interface for communicating FICON protocol 41. The LAN or WAN network connection with its peer entities. However, the communication with the between Host A8 and Host B9 is facilitated by the architec 55 remote peer entities is performed through IBM standard 8232 ture consisting of the Ethernet or Token Ring 47. TCP/IP 46. protocol to support TCP/IP pass-through. At the upper inter SNA45 and the applications 44. Note the additional hardware face of this emulation layer, a set of service primitives are and protocols that are needed in order to provide host to host provided so that the user of this emulation layer such as the communication and to access applications. TCP/IP stack in this particular case, could communicate FIG. 3 depicts the network configuration according to the 60 using these primitives. The emulation layer 57 encapsulates present invention that facilitate direct communication the TCP/IP packets in 8232 protocol frames 66 with the 8232 between two hosts through a SAN. The SAN 17 utilizes an protocol header 67 attached before transmitting them to a architecture consisting of TCP/IP and system network archi remote peer entity or services. The 8232 protocol frames 67 tecture (SNA) over FICON. Host A 14 utilizes SCSI & are then transmitted using the FICON layer. Similarly, the FICON protocols over FC. Host B utilizes FICON protocol 65 emulation layer will strip the 8232 header 68 from the over FC. This connection scheme allows direct communica received 8232 protocol frames from the underlying FICON tion between Host A 14 and Host B 15 through the SAN 17. layer before handing over the encapsulation and decapsula US 7,702,762 B1 5 6 tion, the emulation layer also handles the control frames to protocol in a non-ESCON protocol manner, the storage manage the 8232 protocol activity. devices exclusive of the second host; and The 3172 emulation could support Ethernet, FDDI and means for communicating directly between the first and TokenRing LAN types and accordingly, it exposes the appro second hosts using the storage area network protocol in priate interfaces to the TCP/IP stack above it. a non-ESCON protocol manner without passing through a storage device. ADVANTAGES OVER THE PRIOR ART 2. The system of claim 1, wherein the storage area network protocol is a FICON protocol. The present invention has an advantage over the prior artin 3. The system of claim 1, wherein the means for commu that no special FICON based hardware adapters are required, 10 nicating comprises: unlike ESCON based architecture, in order to provide end means at the first host for translating between the storage to-host network connectivity. Instead the FICON based archi area network protocol and a host-to-host communica tecture uses standard Fibre Channel adapters. This allows the tions protocol selected from the group consisting of SAN infrastructure to be leveraged for physical connectivity TCP/IP and SNA. needs. Also, the distance between the end-hosts is no longer a 15 4. A system for facilitating the communications of a first limiting factor from a cost perspective because the connec host comprising: tivity can be easily extended at a very reduced price through means for communicating with a second host using a stor WAN networks. Since no special hardware other than the age area network protocol in a non-ESCON protocol standard Fibre Channel hardware adapter is required, there is manner, and a significant reduction in product development or test cycles. means for communicating with a storage area network Also there is no additional cost associated with software using the storage area network protocol in a non-ES driver development for the adapter. Ultimately the present CON protocol manner, the storage area network includ invention will result in better time-to-market (TTM) of prod ing a plurality of storage devices exclusive of the first ucts, significant cost reductions and greater product flexibil host and the second host. 25 5. The system of claim 4, wherein the storage area network protocol is a FICON protocol. Alternative Embodiments 6. The system of claim 4, wherein the means for commu nicating comprises: FIG. 11 shows an article of manufacture or a computer means for translating between the storage area network program product including a signal bearing media for storing 30 protocol; and thereon program means for carrying out the method of this communications protocol selected from the group consist invention in the system of FIGS. 3 and 8. While the present ing of TCP/IP and SNA. invention has been described in the context of a system and 7. A method for communicating between a first host and methodofoperation, the mechanisms of the present invention second host comprising: are capable of being distributed as a program-product in a 35 communicating between a first host and a storage area variety of forms, and the present invention applies equally network using a storage area network protocol in a non regardless of the particular type of signal bearing media used ESCON protocol manner, the storage area network to actually carry out the distribution. Examples of signal including a plurality of storage devices exclusive of the bearing media include recordable media (such as digital and first host; analog communications links, including fiber and wireless 40 communicating between a second host and the storage area communications links). network using the storage area network protocol in a An example of such an article of manufacture is illustrated non-ESCON protocol manner, the storage devices in FIG.11 as pre-recorded CD-ROM 1002. CD-ROM 1002 is exclusive of the second host; and intended for use with a data processing system, and includes communicating directly between the first and second hosts optical storage medium 1004, and program means 1006, 45 using the storage area network protocol in a non-ES 1008, 1010 and 1012 recorded thereon for causing the system CON protocol manner without passing through a storage of FIGS. 3 and 8, to practice steps of this invention. It will be device. understood that such apparatus and articles of manufacture all 8. The method of claim 7, wherein the storage area network fall within the spirit and scope of this invention. protocol is a FICON protocol. It will be appreciated that, although specific embodiments 50 9. The method of claim 8, wherein the step of communi of the invention have been described herein for purposes of cating directly between the first and second hosts Supports a illustration, various modifications may be made without high-speed file transfer application. departing from the spirit and scope of the invention. In par 10. The method of claim 9, wherein the file transfer appli ticular, other protocols could be used over the SAN/FICON cation is supported by 3088 emulation. architecture. Accordingly, the scope of protection of this 55 11. The method of claim 7, wherein the step of communi invention is limited only by the following claims and their cating between the first and second hosts comprises: equivalents. the first host translating between the storage area network I claim: protocol and a host-to-host communications protocol. 1. A system for communication between a first host and 12. The method of claim 11, wherein the host-to-host com second host comprising: 60 munications protocol is TCP/IP. means for communicating between a first host and a stor 13. The method of claim 11, where the host-to-host proto age area network using a storage area network protocol col is SNA. in a non-ESCON protocol manner, the storage area net 14. The method of claim 12, wherein the storage area work including a plurality of storage devices exclusive network protocol is a FICON protocol. of the first host; 65 15. The method of claim 14, wherein the step of commu means for communicating between a second host and the nicating directly between the first and second hosts com storage area network using the storage area network prises: US 7,702,762 B1 7 8 encapsulating TCP/IP packets from the first host in 8232 means in the medium for communicating between the first protocol frames; host and the second host using the storage are network transmitting the 8232 protocol frames to the second host protocol in a non-ESCON protocol manner. using the FICON protocol; and 20. The article of claim 19, wherein the storage area net decapsulating the TCP/IP packets from the 8232 protocol 5 work protocol is a FICON protocol. frames at the second host. 21. The article of claim 19, wherein the means in the 16. A method for facilitating the communications of a first medium for communicating comprises: host comprising: means in the medium at the first host for translating communicating with a second host using a storage area between the storage area network protocol; and network protocol in a non-ESCON protocol manner; 10 a host-to-host communications protocol selected from the and group consisting of TCP/IP and SNA. communicating with a storage area network using the stor 22. The article of claim 19, wherein the medium is selected age area network protocol in a non-ESCON protocol from the group consisting of magnetic, optical, biological and manner, the storage area network including a plurality of atomic data storage media. storage devices exclusive of the first host and the second 15 23. An article for communicating with a first host compris host. ing: 17. The method of claim 16, wherein the storage area a tangible recordable data storage medium; and network protocol is a FICON protocol. means in the medium for communicating with a storage 18. The method of claim 16, wherein the steps for commu area network, and with a second host using a storage area nicating comprise: network protocol in a non-ESCON protocol manner, the translating between the storage area network protocol and storage area network including a plurality of storage a communications protocol selected from the group con devices exclusive of the first host and the second host. sisting of TCP/IP and SNA. 24. The article of claim 23, wherein the storage area net 19. An article for communicating between a first host and a work protocol is a FICON protocol. second host comprising: 25 25. The article of claim 23, wherein the means in the a tangible recordable data storage medium; medium for communicating comprises: means in the medium for communicating between a first means in the medium for translating between the storage host and a storage area network using a storage area area network protocol; and network protocol in a non-ESCON protocol manner, the means in the medium for a host-to-host communications storage area network including a plurality of storage 30 protocol selected from the group consisting of TCP/IP devices exclusive of the first host; and SNA. means in the medium for communicating between a second 26. The article of claim 23, wherein the medium is selected host and the storage area network using a storage area from the group consisting of magnetic, optical, biological and network protocol in a non-ESCON protocol manner, the atomic data storage media. storage devices exclusive of the second host; and k k k k k