25 Gigabit Ethernet (25GbE) emerged from the development of 100 Gigabit Ethernet( 100GbE). While the first developments of 100GbE aggregated ten lanes with 10 Gbit/s each, the further developments had four 25 Gbit/s lanes.
By reducing the number of lanes, the chips consume less energy and can be manufactured at lower cost. These factors form a major cost factor, especially in data centers, because energy consumption entails higher costs for cooling. This development forms the basis of 25GbE and 50GbE, which works with two lanes. By working with much fewer switches, the energy costs are reduced considerably.
25 Gigabit Ethernet is a transmission technology for data centers, which was developed by IEEE working group802.3by. On the one hand, this technology works with twinaxial cables, and on the other hand, it relies on point-to-point connections via the traces of the backplane circuit board. Further development of 25GbE took place in the IEEE 802.3cc working group and the use of single- mode fibers. This 25GbE transmission technology targets enterprise, campus and metro Ethernet applications with ranges up to 10 km and 40 km over duplex monomode fibers.
25-Gigabit Ethernet uses the same nomenclature for the 25GbE interfaces as the other Gigabit Ethernet technologies. As for the 802.3by specifications, it specifies 25GBase-KR interfaces for backplane Ethernet, 25GBase- CR-S(short) and 25GBase-CR-L (long) for 3 m and 5 m twinaxial cables for internal rack cabling and cabling between racks. In addition, with the 25GBase-SRinterface, there is one for multimode fibers of OM classes OM3 (70 m) and OM4 (100 m). In addition, with 25GBase-T there is an interface with four-pair symmetrical copper cabling, known as 4 Pair Power over Ethernet( 4PPoE). This standard was specified by the IEEE working group 802.1bq. The bridgeable distance is approximately 30 m, the base frequency is 1.25 GHz, and the data rate is 2 GBaud. 25GBase-T is backward compatible to 10GBase-T.
The 802.3cc working group has specified two interfaces for duplex monomode fiber: 25GBase-LR for distances of 10 km and 25GBase- ER for 40 km. All interfaces use Non Return to Zero( NRZ) as coding method.
25Gb Ethernet ni aina ya mtandao wa mtandao wa 100Gb Ethernet. Wakati maendeleo ya kwanza ya 100GbE yalijumuisha mistari kumi na 10Gbps kila moja, maendeleo ya baadaye yalikuwa na mistari minne ya 25Gbps. Kwa kupunguza idadi ya mistari, chips hutumia nishati kidogo na inaweza kutengenezwa kwa gharama ya chini. Vipengele hivi huunda sababu kubwa ya gharama, hasa katika vituo vya data, kwa sababu matumizi ya nishati yanahusisha gharama za juu za baridi. Uendelezaji huu unaunda msingi wa 25GbE na 50GbE, ambayo inafanya kazi na mistari miwili. Kwa kufanya kazi na swichi chache sana, gharama za nishati hupunguzwa sana. 25Gb Ethernet ni teknolojia ya uhamisho wa data ya data, ambayo ilitengenezwa na IEEE Working Group 802.3. Kwa upande mmoja, teknolojia hii inafanya kazi na nyaya za twinaxial, na kwa upande mwingine, inategemea uhusiano wa uhakika-kwa-ncha kupitia alama za bodi ya mzunguko wa backplane. Kwa sasa, teknolojia ya 25GbE inapatikana katika IEEE 802.3, ambayo inazingatia matumizi ya fiber ya single-mode. Teknolojia ya usafirishaji wa 25GbE inazingatia matumizi ya biashara, chuo kikuu na metro Ethernet na kufikia hadi 10km na 40km juu ya nyuzi za duplex monomode. 25Gb Ethernet ni moja ya teknolojia za kwanza za 25Gb Ethernet. "Kama kwa vipimo vya 802.3, inataja ""25GB base-KR"" interfaces kwa ajili ya backplane Ethernet, ""25GB base-CR-S"" (fupi) na ""25GB base-CR-L"" (mrefu) kwa ajili ya 3m na 5m twinaxial cables kwa ajili ya ndani rack cabling na cabling kati ya racks." Kwa upande mwingine, kwa sababu ya kuunganisha kwa 25GB, kuna njia ya kuunganisha kwa fiber ya multimode ya OM3 (mm) na OM4 (mm). "Kupitia 25GB-T, unaweza kutumia ""4 Pairs Power Over Ethernet"" (PPoE) na ""4 Pairs Power Over Ethernet"" (PPC)." Kiwango hiki kilifafanuliwa na kikundi cha kazi cha IEEE 802.1bq. Uwezo wa kuunganisha ni karibu mita 30, mzunguko wa msingi ni 1.25 GHz, na kiwango cha data ni 2 Gbaud. 25GB ya msingi ni backward-ambatana na 10GB ya msingi. 802.3CC ina interface mbili kwa ajili ya duplex monomode fiber: 25GB-LR kwa umbali wa 10km na 25GB-ER kwa umbali wa 40km. Interfaces zote kutumia Non Return to Zero (NRZ) kama mbinu coding.